The widow of a police officer shot and killed while on duty in Croydon has paid a moving tribute to him amid ongoing investigations surrounding his death.

Matiu Ratana's partner Su Bushby described him as a "lovely man" and a "gentle giant" in a statement published by the Metropolitan Police Monday afternoon (September 28).

In it, she said she had few words to describe what she was feeling after Matt was shot dead by a man he was detaining at Croydon Custody Suite in the early hours of Friday (September 25).

Nevertheless she paid tribute to his memory and said she would always remember him and his impact:

"There aren’t really any words for how I am feeling right now about the loss of Matt; about losing someone I loved, and was so close to, in such a tragic manner.

"I know Matt touched many, many people’s lives with his friendliness, patience, kindness, enthusiasm and caring ways," Su said.

"I had the pleasure of sharing five years of my life with this lovely man - my gentle giant, with his infectious smile and big heart. I think of him with tenderness and love.

"Matt was my partner, friend, confidant, support and soul mate.

"He will be greatly missed but never forgotten. Matt will always be in my head and in my heart," she added.

The tribute arrived after police arrested a man in Norwich on Sunday who is suspected of supplying the firearm used in Matt's killing.

The suspect for Matt’s shooting, a 23-year-old man who had been arrested earlier that night, remains in hospital.

He is in a critical condition and consequently police said they are still not able to speak to him.