Duncan Garner's emotional tribute after weekend tragedy hits his family

Duncan Garner has paid an emotional tribute after he revealed he knew a man who was killed in a car crash in west Auckland at the weekend.

The AM Show host says his family had become close to the man, who coached his son's representative rugby team last year.

Garner said he was devastated, adding his friend was a "special guy".

"He was a damn good coach - he believed in my son.

"I'm devastated by it - he was my friend, so I've lost a friend."

Police confirmed a man died in the single-car crash on Glengarry Rd, Glen Eden just before 4am Sunday.

Garner also revealed he had been looking after the man's son on Saturday night.

"He's a friend of my son's, so we had his boy - he's a great little boy.

"We'd been tenpin bowling, went home, went to sleep, [had a] knock on the door early in the morning - got that dreaded doorknock.

"My deepest sympathy and love to the family - my deepest thoughts are with you," Garner said.

The man was initially trapped before being taken to Auckland Hospital where he later died, police said.

The Serious Crash Unit examined the scene of the crash on Sunday.