Police Commissioner Andrew Coster says police lost a member of their whānau when a New Zealand sergeant was shot dead in London yesterday.
New Zealand-born Sergeant Matiu Ratana, known as Matt, was two months from retiring when he was shot in the chest in Croydon.
Ratana was shot while a suspect, still in handcuffs, was about to be searched at a custody centre.
After the shooting, at about 02:15 BST, the suspect, 23, is thought to have turned the firearm on himself. He is in a critical condition in hospital.
Coster said policing was a family and while Ratana spent most of his career in the UK, he would always be a part of the New Zealand Police
He said the 54-year-old sergeant joined the New Zealand Police as part of the first British High Commission Wing in 2003 and served in Auckland City and Counties Manukau until 2008, before returning to the UK.
Met Police Commissioner Cressida Dick described Ratana as "a big guy" who was "big in heart".
Dick said Ratana had been well known locally and beyond.
"He will be remembered so fondly in Croydon and missed there, as well as in the Met and the rugby world," she said.
A minute's silence was held at 16:00 BST at New Scotland Yard and Croydon Police Station to pay tribute to the officer.
Ratana had served with the Met for almost 30 years having moved to the UK in 1989.
The 54-year-old was originally from Hawke's Bay and was educated at Palmerston North Boys' High School.
He had served with the Met in various parts of London including Hackney and Selhurst, with his last posting as custody sergeant in Croydon, where he managed suspects who are brought into the cells.
He was on duty in that role at the Windmill Road centre when he was shot dead at about 02:15.
The BBC has been told the shooting happened during questioning of the suspect about Covid-19.
Sir Peter Fahy, the former chief constable of Greater Manchester Police, told the BBC: "It's very callous and it's obviously going to cause a lot of fear for police officers. It's very upsetting for them as it makes them feel so vulnerable."
He said the circumstances surrounding the death appeared to be "incredibly unusual", adding: "There are procedures of searching prisoners before they are taken to police station in vans or in cars, they're searched again when they get to police stations and there are additional procedures because of screening for Covid.
"It will be important to get out fairly quickly the circumstances to see if there's anything that can be learnt about it."
Rugby connections pay tribute
Outside work Sgt Ratana was a highly experienced rugby union coach, leading teams in Worthing, close to Goring-by-Sea where he then lived and in East Grinstead, where he was living when he died.
Sergeant Ratana was head coach at East Grinstead Rugby Club, and a team manager, Byron Tompkinson, said he brought a Kiwi influence to the club.
"He's probably the most influential person who has made a huge impact on many young people's lives at the East Grinstead Rugby Club. He's going to be sorely missed."
Tompkinson said the club will decide on a suitable tribute for a man who poured his heart and soul into rugby.
Ryan Morlen, assistant head coach at East Grinstead Rugby Club, described the 54-year-old as "an absolutely lovely bloke".
A group of teenage boys had been at a training session with the East Grinstead rugby club Matt Ratana just hours before he was killed.
The father of one of them, Antony Weller, said the players were devastated.
"They absolutely loved him. They saw him as a rugby coach, they respected him, they felt like he was an older brother, he wasn't a stern dad or anything like that. He wanted to develop and help them."
The video below shows Ratana showcasing rugby.
Ardern offers condolences
Prime Minister Jacinda Ardern said she was "incredibly sad" to hear about the death.
In a post on Facebook, Ardern wrote: "To all Matiu's whānau across the world, we share your sorrow and have all our condolences."
Ratana's first cousin is the Labour MP Adrian Rurawhe, who says he last saw him six years ago when he came back to New Zealand for his father's tangi.
He said his cousin had clear leadership qualities.
"He was fearless in some ways ... he also wasn't afraid to ask questions about his culture. He was really proud of being Māori."
Rurawhe said the whānau is in shock over the death.
Earlier, BBC Home Affairs correspondent Danny Shaw said it was believed the suspect was known to counter-terrorism police having been on their radar in the past, though the Met has not officially confirmed that.
The Independent Office for Police Conduct (IOPC) said the man was arrested on suspicion of possession of Class B drugs with intent to supply and possession of ammunition.
He was handcuffed with his hands behind his back and taken to the Croydon Custody Centre in a police vehicle, before being escorted into the building.
The shots were fired as officers prepared to search the suspect, who was still handcuffed, with a metal detector, the IOPC said.
"A non-police issue firearm, which appears to be a revolver, has been recovered from the scene. Further ballistic work will be required," said IOPC regional director Sal Naseem.
The Met said a murder investigation was under way, but the shooting was not being treated as a counter-terrorism incident.
Dick said she understood "the great concern about how this happened" and that officers "will establish the facts".
"We owe it to Matt, his loved ones and all other officers. But we need to give investigators space to do their job," she said.
London's Mayor Sadiq Khan earlier said the police were currently "reviewing the safety of custody suites" and "there could be changes very soon".
- BBC, RNZ