Immigration Minister Peter Dutton says he has complete confidence in Papua New Guinea's authorities after reports asylum seekers were arrested and assaulted by PNG police and immigration officers on New Year's Eve.

Mr Dutton's comments follow those from a PNG politician who has justified the actions of police, which allegedly left the two Iranian men with numerous broken bones.

Manus Island MP Ron Knight, who says he was present at the incident, tweeted the two men were "very drunk" at the time, stopping vehicles and chasing members of the public.

He said the pair assaulted two immigration officials before police arrived, adding that "the police here have to be brutal".

The Refugee Advocate Coalition has called on the Australian Government to investigate the matter, but Mr Dutton today said he has confidence in PNG authorities.

The injured faces of two Manus Island asylum seekers who were allegedly beaten by PNG police. ( Supplied: Refugee Action Coalition )

"Others who pass judgement before they have any of the facts available need to be a little more circumspect," he said.

"If people have been out celebrating or out drinking, or consuming alcohol, or whatever the case may have been on New Year's Eve, and there's been an interaction with the police regardless of where it is, I think we're best advised to wait for all of the facts to come out."

Refugee Action Coalition spokesman Ian Rintoul said the men had done nothing wrong when they were assaulted by the authorities.

Mr Rintoul said the men suffered broken bones, cuts and bruises.