The family of a "fearless" police officer killed in his own station have paid moving tribute to him after the horrifying shooting.

Matiu Ratana, 54, died after being shot at Croydon Custody Centre in the early hours of Friday.

The officer, also known as Matt, joined the police in 1991 and served in the force for almost 30 years.

Sgt Ratana’s first cousin Adrian Rurawhe​, MP for Te Tai Hauāuru, told Stuff: “We’re all devastated that we’ve lost our cousin, but also to hear about the way he has been killed.

“He was awesome, very outgoing and a natural-born leader. Some people have to learn how to be a leader, but it just came naturally to him.”

Matiu Ratana died in the early hours of Friday morning

He added: "He was really proud to be a police officer, he was also really proud to be Māori from New Zealand."

Mr Rurawhe​ said that his cousin loved his job as a police officer.

David Bovey, rector of Palmerston North Boys’ High School where Sgt Ratana was a student, said he was a “top fella” who was remembered very fondly.

The 54-year-old had just finished coaching a rugby session when he began leading the night shift late on Thursday.

The police officer, also known as Matt, had joined the force in 1991

He died several hours later after being shot in the chest as alleged killer had reportedly been taken to the custody suite after being arrested by two special constables.

The suspect is currently in hospital.

It is understood that Sgt Ratana was shot as he searched the suspect with a metal detector, according to a statement from the Independent Office for Police Conduct (IOPC).

Sgt Ratana, originally from Hawke's Bay in New Zealand, came to London in 1989, two years before joining the force.

One friend said Sgt Ratana was looking forward to retirement and told the PA news agency: "I think he earned his stripes, if you ask me."

Matt Ratana was remember by his family following his death

A murder probe has been launched and investigators from the Independent Office for Police Conduct (IOPC) watchdog attended the scene.

The IOPC have obtained CCTV from the custody centre as well as body-worn video footage from the officers present.

These will now be reviewed in the coming days, and initial accounts from the officers present will also be taken.

The suspect was arrested by regular officers following a stop and search, then handcuffed behind his back before being taken to the station in a police vehicle.

The IOPC said he was taken into the building and sat in a holding area in the custody suite, then opened fire while still in handcuffs as officers prepared to search him with a metal detector.

IOPC regional director Sal Naseem said: "It is at that point that shots were fired resulting in the fatal injuries to the officer and critical injuries to the man.

"A non-police issue firearm, which appears to be a revolver, has been recovered from the scene. Further ballistic work will be required."