Greens senator Nick McKim will use a trip to Manus Island next week to "get to the bottom" of what sparked a shooting at the Manus Island detention centre on Good Friday.

Explanations of the shooting have been conflicting and contradictory with Mr Dutton saying it is "indisputable" that shots were fired by soldiers concerned about the welfare of a young boy.

But Manus Island police commander David Yapu said the boy was not related to the shooting and there were no concerns for his welfare and no official complaint.

Mr Yapu instead blamed the shooting on drunken soldiers at the nearby naval base, who allegedly had a fight with refugees playing soccer.

Sorry, this video has expired Peter Dutton defends comments linking Manus shooting to concerns for safety of young boy

Senator McKim said he would discuss the shooting with Papua New Guinea police while visiting Manus Island.

"I've put in requests to meet with senior Papua New Guinean police both in Port Moresby and on Manus Island because, given Peter Dutton's comments about how the Good Friday attacks occurred and why they occurred, I want to help Australians understand what happened," he said.

"I haven't signed up to any conditions, either with the Papua New Guinean Government or the Australian Government.

"Now we're told consistently that the detention centre is an open centre so it's my intention to simply go to the centre."

Mr Dutton said the suggestion a PNG navy officer fired bullets into the detention centre because of a fight about soccer alone was a "nonsense".

"There was a build-up for a period of time, and I think it was on a slow boil for a period of time, and I think it boiled over in relation to that particular incident," he told Sky News.

Mr Dutton said there had been numerous allegations about sexual assault at the detention centre, which is part of a PNG naval base and adjacent to the local community.

"It is quite integrated and there have been circumstances that have caused us concern and that's been consistent in terms of the briefings that I have received," he said.

The minister said he had received "clear and consistent" advice that the shooting was "not an issue that just boiled up with one incident on a soccer field".

"There was — certainly the case in terms of all the information I have received — advice about certain behaviours that concern me, concern me greatly," Mr Dutton told Sky News.

"I have been very adamant in relation to the stance that I have taken and I don't resile from that one bit."

Mr Dutton has called on a number of media outlets, including the ABC and Fairfax Media, to apologise for their reporting of the shooting.