Auckland police say the man they are seeking over a fatal knife attack in the suburb of Mt Albert this week is "extremely dangerous" and should not be approached.

The victim's body was found near the Roy Clements Treeway at about 6.45pm on Tuesday.

Speaking to media, Detective Chris Barry said 22-year-old Christian Eteuati is being sought in relation to the death.

Eteuati is known to frequent Sandringham and West Auckland.

"We do consider Mr Eteuati to be a danger. We would advise people if they are walking in the area at night, walk in well-lit areas."

People should also not walk in the area alone, Barry said.

It was not believed that the victim was known to the offender, Barry said.

He said this was a "brutal attack" and involved a knife as a weapon.

"I can advise it was multiple injuries sustained by the victim," Barry said.

Police had received information from the public overnight, but their focus was on finding the man.

Police would not release any details about the victim yet.

Police cordon in Mt Albert where the body of a local man was found.

Police guard the scene at the Roy Clements Treeway in Mt Albert on Thursday. Photo: RNZ / Marika Khabazi

The walkway is closed as part of the police investigation, but is ordinarily a popular route for school students.

Mt Albert Grammar has warned its pupils to be aware of their surroundings, and make safe choices walking to and from school.

In a letter to parents, headmaster Patrick Drumm said students should should walk in groups if possible, not wear earpods, and choose well-lit areas if walking at night.

The body was found near the Roy Clements Treeway at about 6.45pm on 24 May and police believe the man was attacked.

Roy Clements Treeway

Roy Clements Treeway. Photo: Supplied