Pictures show the sunshine villa where drug baron John Gilligan kept a gun thought to have been used to kill Irish journalist Veronica Guerin in 1996.

Armed police broke down his door with a battering ram after storming up a side path by his pool.

Well-placed sources say the 68-year-old was caught “red-handed” preparing a delivery to Ireland of marihuana and prescription-only powerful pills known as Zimmos which heroin addicts use to help them sleep and numb pain.

Two more suspects were held in a car outside with a further two boxes due to be sent via post.

The gun was found in the garden of the Costa Blanca property, wrapped in plastic and hidden under gravel and cloth normally used to stop weeds growing through.

Spanish police have already confirmed it is a rare Colt Python .357 Magnum and is the same ‘make and model’ to the one Ms Guerin was killed with in an ambush at a red light on the outskirts of Dublin in June 1996.

A police source said it had been hidden “like a souvenir.” Gilligan was acquitted of ordering the reporter’s murder in 2001 but convicted of importing two tons of cannabis resin worth £32 million and sentenced to 28 years in prison.

Gilligan was living at the £273,000 four-bed villa, on a nondescript residential estate a ten-minute drive from Torrevieja town centre, with the new woman in his life following his split from wife Geraldine.

The British national, who is in her late fifties and called Sharon, was the only woman held in the Spanish police raids on Tuesday which were sparked by an investigation last year into a drugs smuggling gang allegedly led by Gilligan.

Two of the other four held, including Gilligan’s son Darren, are Irish and the others a Spanish and Colombian man described by police sources as “mere employees” of the drugs baron.

Police filmed the gangster, who survived an assassination attempt after his release following 17 years behind bars, being barked at to lie on the floor of his kitchen and handcuffed.

He was later led out to his garden so he could watch police dig up the gun which is now the focus of an investigation involving Gardai and Spanish cops.

A court official, confirming Gilligan had been remanded in custody on Thursday after appearing before a duty judge in a closed court hearing in Torrevieja, added: “All six suspects are being investigated as part of a criminal probe opened for crimes against public health, unlawful possession of firearms and membership of a criminal gang.”

Gilligan, the only one of the six detainees remanded in jail, has not yet been formally charged with any crime as charges are only laid shortly before trial in Spain.

Criminal investigations of the sort Gilligan now faces can take months and even years in some cases to complete.

He can be held in custody on remand for up to four years without trial, although it is normal for most suspects to be released on bail after a maximum of two years.

Ms Guerin was working for the Sunday Independent when she was shot dead at a red traffic light on the Naas Dual Carriageway near Newlands Cross on the outskirts of Dublin on June 26, 1996.

The gun used to shoot her by one of two men on a motorbike was never found.

Her funeral was attended by Irish Taoiseach John Bruton, who described her murder as an “attack on democracy.”

The assassination led to the formation of Ireland’s Criminal Assets Bureau targeting organised criminals’ illegally acquired assets.

The 2003 biographical crime film Veronica Guerin, directed by Joel Schumacher and starring Cate Blanchett in the title role, was the second to be inspired by the reporter’s life.

Gilligan was tried for Ms Guerin’s murder with other members of his drugs gang after a former soldier who prepared the gun used to kill her agreed to turn state’s witness and was given immunity from prosecution.

Judge Darmuid O’Donovan admitted as he acquitted him at Dublin’s Special Criminal Court he had “grave suspicions” the drugs baron was involved in the killing.

Former friend Brian ‘Tosser’ Meehan was convicted of the crime reporter’s murder and remains in prison.