Immigration Minister Peter Dutton says it is "indisputable" that concerns for the safety of a young boy were directly related to a shooting on the Manus Island detention centre.

Key points: Mr Dutton told Insiders he received "clear" briefings from officials on the island

Mr Dutton told Insiders he received "clear" briefings from officials on the island He stood by his earlier suggestion that there were fears the boy had been sexually assaulted

He stood by his earlier suggestion that there were fears the boy had been sexually assaulted Two have been accused of sexual assault, he said

Two have been accused of sexual assault, he said The Manus police commander says the boy was unrelated to the shooting

Mr Dutton said earlier this week that Papua New Guinea soldiers fired bullets into the centre after reports a five-year-old had been led into the detention centre.

He suggested local residents and soldiers feared the boy had been sexually assaulted inside the detention centre.

But Manus province police commander David Yapu said the incident involving the boy — who he said was 10 years old — was unrelated and there was no concern for his safety.

Mr Dutton stood by his comments on Insiders on Sunday morning, saying he had received "succinct and clear" briefings from officials on the island.

"The point that I was making and certainly the clear advice I received was that there had been a ramping up in terms of the mood on the ground over a period of time," he said.

Mr Dutton confirmed two people had been accused of sexual assault but said the matter would be dealt with by the PNG police.

"Of course it is true," Mr Dutton told Insiders.

"I was asked why the mood was elevated on the ground on Manus Island and these two incidents [including the shooting itself] fed directly into that — that is indisputable."

"If you are asking me about why there was an elevation in the angst between those that are living on the naval base on Manus Island, this was part of it, and that was the clear advice to me."

Mr Yapu said the boy was brought into the centre to be given food some days before the attack by the soldiers.

"He was given some fruit by the residents in the centre and then he was taken out again," he said.

"So there was nothing done to him and also there was no official complaint by the parents of that small boy."

Dutton says decision on CCTV footage is down to PNG government

Sorry, this video has expired Reports of shots fired at Manus Island detention centre

Asylum seekers in the centre said the boy was begging for food at the centre entrance and that staff were aware that he was brought inside to be fed.

They have urged the Australian Government to release CCTV footage from the many cameras at the centre, saying it will show their account was correct.

Mr Dutton would not commit to releasing the footage but said any decision to do so would be made by the PNG Government.

"We will continue to release footage as is the normal practice now, I am not making an exception one way or the other in relation to this case," he said.

"If it is appropriate for it and that has been the practice in the past, then that will happen, but that is a matter for the PNG Government."

Mr Dutton would not comment on contradicting reports from the PNG police, including the age of the boy, saying the matters would be resolved by a police investigation.

"Shots being fired or behaviour as it is reported is completely unacceptable and it should be investigated," he said.

Labor's Shadow Defence Minister Richard Marles would not comment on the shooting but urged against speculation.

"What I do know from previous incidents is that quite often what is in the public domain early on ends up being very different from what ultimately happened," he told Sky News.