Early in 1995, the glamorous former wife of fashion magnate Maurizio Gucci went shopping in Milan for a special outfit.
This in itself was not unusual since in those days Patrizia Reggiani was something of a designer clothes horse, fond of colourful frocks and film star dark glasses.
Except on this occasion she bought an elegant black suit and veil to wear to 46-year-old Maurizio's funeral – even though he was very much alive and, by all accounts, in rude health. Patrizia knew, however, what was coming next.
Springing up the steps of his offices on Milan's elegant Via Palestro one morning three months later, Maurizio was approached from behind by a dark-haired man who pulled out a gun and put three bullets in his back and a fourth in his head.
The murder transfixed Italy. Before their acrimonious split, Maurizio, the last of the Gucci family dynasty to run the luxury brand, and Patrizia, his flamboyant, strong-willed wife, had been a celebrity power couple.
A tip-off led to Patrizia's arrest in 1997. A search of her Cartier diary revealed she had marked the date of Maurizio's murder with the word 'Paradise' and after a sensational trial, she was convicted of hiring a hitman to kill him, earning herself the sobriquet Black Widow.
Patrizia Reggiani's ex-best friend Giuseppina 'Pina' Auriemma (left) was convicted of acting as the 'middle woman' in the hit of Maurizio Gucci, liaising with the organiser of the murder
Few in this high-living couple's gilded world were better placed than Patrizia's former best friend Giuseppina 'Pina' Auriemma to observe her downfall – a story of love, betrayal, sexual jealousy and bloody revenge set against a high-fashion backdrop that is now being retold in Ridley Scott's film House Of Gucci.
Speaking to The Mail on Sunday in her first interview, Pina recalls Patrizia's ruthlessness, typified, she says, by the prematurely purchased funeral outfit on a shopping trip that has remained secret until now.
And Pina reveals her lifelong bitterness at being drawn into the Black Widow's web and being ostracised from her family. For Pina was convicted of acting as the 'middle woman' in the hit, liaising with the organiser of the murder.
After her arrest, Pina was described in the Italian media as a maga – sorcerer or fortune-teller – and dubbed the Black Witch.
Hitting back at her old friend, who is played by Lady Gaga in the film, Pina, 75, says: 'She is evil. My life has been completely ruined by that woman.
'I thought Patrizia was a fun and exciting person when we first met, but now I see that she is a shallow narcissist who only cares about money and will step on anyone to get what she wants.'
Her bitterness stems in no small part from Patrizia's insistence that Pina was to blame for the murder, which she vehemently denies. Both women served their time in San Vittore prison in Milan, where for years they determinedly avoided one another.
At Patrizia's trial, it was claimed she ordered her ex-husband's murder because of her 'insatiable hatred' of his new life with another woman.
There were other factors too. Maurizio had been forced to sell his stake in Gucci 18 months before he died, a decision Patrizia never forgave, since everything 'she was stemmed from being a Gucci', says a Milanese fashion writer.
'It was her whole identity, even as an ex-wife. She was furious with Maurizio for selling out.'
Pina says that in the aftermath of the break-up, Patrizia threatened to throw herself off the balcony of her luxury apartment, became hooked on anti-anxiety drugs and, in rage, once tore apart the leather walls of an elevator with her nails.
In the film, Pina, played by Salma Hayek, is depicted as an eccentric, dowdy mystic whom Patrizia contacts after watching her on a clairvoyant TV show.
It was claimed Patrizia ordered her ex-husband's murder due to her 'hatred' of his new life with another woman. Pictured: Lady Gaga as Patrizia and Adam Driver as Maurizio
The reality, Pina says, is very different. 'I have never practised magic or fortune telling – I have no interest in it – and it is defamatory to say I do.
'It was Patrizia and Maurizio that were obsessed with tarot cards and mediums. Whenever they arrived in a new place, the first thing they would do was find the local psychic.'
The two women met by chance in the late 1970s at the Excelsior spa hotel on the volcanic Italian island of Ischia.
'I liked Patrizia immediately,' Pina says. 'We were both young and fun, in our 30s. I had no idea who she was as she wasn't famous back then, but I remember she was wearing a pearl bathing suit and she was dripping in jewellery.
'She refused to eat, as was the custom of high society women back then, so we spent most of our time gossiping in the spa. At the end of the week, her husband joined us, which made it more fun as he liked to eat well and drink champagne.'
Pina's impression of Maurizio was that he 'seemed like a nice person, if a bit gullible and naïve, and we got on well'.
'You could tell Patrizia wore the trousers in the relationship and he seemed completely besotted with her. Whenever she crossed a room, he could not take his eyes off her.'
Following the death of his father in 1983, Maurizio inherited 50 per cent of the company but the Gucci brand had lost its lustre, thanks to its famous name being over-licensed.
According to Pina, her socialite friend believed she was stronger, and therefore more 'Gucci', than anyone else in the family. She pushed Maurizio into a power struggle with his uncle Aldo, played by Al Pacino in the film.
Her ambitions to be the First Lady of Gucci hit the buffers, however, when she was out-manoeuvred by the firm's executives.
She was forced into life as a bored housewife, albeit one with a 200ft yacht, a ski chalet in St Moritz, a holiday home in Acapulco and a farm in Connecticut. At one point, she was said to be spending £9,000 a month on orchids.
What she really wanted, though, was respect, which proved impossible to buy.
Pina says: 'Patrizia would call me at all times of day and night when she was unhappy, with no respect for whether I was sleeping. Patrizia's mother came from a poor family so other women in her circle looked down on her.
'She was always referred to as 'daughter of a waitress' and she resented this, saying, 'I am Mrs Gucci'.'
Because Gucci was never particularly fashionable in the early days of their friendship, Patrizia 'preferred Yves Saint Laurent dresses and Hermes handbags'.
Pina says: 'She could spend thousands at jewellery stores and was very talented at spending her husband's money.
'She would buy the celebrity magazines every morning, but she did not have many famous friends. She might have met Donald Trump once at a party, but that was it and she was not close with Jackie Onassis either – that is fake news.
'Patrizia loved the sea and would regularly take a yacht around the Greek islands or down to Porto Cervo in Sardinia.
Despite being found guilty by a court, Pina, depicted by Salma Hayek (pictured) in House of Gucci, maintains her claim that she did nothing to facilitate the murder
'She was not a big drinker and didn't take drugs or smoke cigarettes so I did not go to lots of glamorous parties with her.
'She was actually a devoted mother and holidays normally involved a private chef and a few glasses of champagne, then bed by 11pm.
'One thing she really enjoyed was reading thrillers and in particular murder mystery novels, which makes me wonder if that's how she got the idea to murder her husband.'
In 1985, Maurizio – played by Star Wars actor Adam Driver in the film – told his wife he was going away on a business trip, from which he never returned.
In reality he was having an affair with married American Sheree McLaughlin, then in her late 20s, whom he was flying back and forth across the Atlantic on Concorde, then picking up in his black Ferrari.
As the film premiered, Sheree said last week: 'I was the catalyst. I didn't want to break up his marriage, but he said that it was already broken.'
Pina remembers things differently. She says: 'One day, Patrizia called me and was crying and screaming down the phone, 'He left me.'
'I couldn't believe it – Maurizio seemed so in love. I told her, 'It's bull****'. But Maurizio was easy to manipulate and that is why he left Patrizia – his friends were telling him to. He was a weak person.
'After the breakup, I flew to New York with Patrizia and we spent a month living in their luxurious fifth-floor apartment in the Olympic Tower she had designed herself with workers flown in from Italy. We did not go out.
'Patrizia was hysterical and I was very worried she would throw herself off the balcony. She was shouting and screaming and could not sleep and she was taking a lot of the anti-anxiety drug Xanax.
'The apartment had an elevator with a leather interior and one day Patrizia tore it apart with her nails. She loved Maurizio, in her way, but she wasn't just upset that her husband had left her. She was upset that she had lost the life she wanted – she wasn't a Gucci any more.'
Patrizia described the £1 million a year alimony she received as 'little more than a plate of lentils'. She continued to use her husband's surname and insisted on referring to him as 'my husband', despite their divorce – yet also made no secret of her loathing for him.
The situation became critical when Maurizio separated from Sheree, got engaged to artist Paola Franchi, and sold his remaining stock in Gucci for around £120 million, meaning Patrizia's daughters Alessandra, 45, and Allegra, 40, would not take over the firm.
According to Pina, Patrizia became obsessed with seizing control of their yacht, the Creole, and the Oeil Bleu, the third of the family's five villas in the Swiss village of St Moritz.
Then, says Pina, 'Patrizia started asking everyone, 'How can I kill my husband?' She thought I could help because I lived in Naples, which is associated with the Mafia.'
Pina recalls Patrizia's ruthlessness, typified, she says, by the prematurely purchased funeral outfit on a shopping trip that was a secret. Pictured: Lady Gaga as Patrizia in House of Gucci
Despite being found guilty by a court, Pina maintains her claim that she did nothing to facilitate the murder. She does admit to taking money from Patrizia, however, and in a bizarre excuse claims it had all been a scam.
'My fashion store had gone bankrupt and I was in debt so I needed the money,' she says. 'Patrizia gave me 150 million lire (£70,000) in cash but I had no intention of finding a hitman – it was a scam.
'I decided, 'If she gives the money to me, she won't be able to kill Maurizio.' After two years passed and Maurizio had not been murdered, Patrizia found a hitman through one of my friends.
'Then, three months before the murder, she went shopping to buy a veil and a black dress.'
Professional hitman Benedetto Ceraulo received a life sentence, while night porter Ivano Savioni, a friend of Pina's and the man alleged to have hired both the driver and the killer, received a 26-year sentence. Getaway driver Orazio Cicala was sentenced to 29 years.
Patrizia was released in 2016 and somehow won a court battle to retain part of her late ex-husband's fortune. Today, she can be spotted wandering around Milan with a pet macaw on her shoulder and recently said of the murder: 'I'm not innocent, but I'm not guilty.'
Despite protesting her innocence, Pina, in a bewildering contradiction, admits being racked with guilt after the murder.
'I was out getting breakfast when I saw on the news that Maurizio had been killed,' she says. 'I was so shocked, I fainted.
'Patrizia called and asked, 'Did you hear the news?' She was completely emotionless and said: 'I'm going to the police station.'
'When they eventually came to arrest me, I said: 'Finally.' I could not carry the guilt any more. There were so many times I stood in front of the police station with the intention of turning myself in, but I was too scared.
'In prison, Patrizia offered me 100 million lire (£36,000) to take the blame. I said no and we spent the rest of our time in prison trying to avoid each other.'
She adds: 'The saddest thing for me is that Patrizia doted on her daughters and said she killed her husband to protect their money and future.
'But now they have fallen out and are fighting over his money and the yacht. It's very sad.'
Whatever the truth of her part in his murder, she says she is haunted by thoughts of Maurizio. 'I'm not sad about prison, I'm sad about the young man that was killed.
'I know I did a terrible thing.'