Scott Morrison.

Immigration Minister Scott Morrison. Photo: Peter Rae

Immigration Minister Scott Morrison has shied away from spelling out what arrangements the government will make for humanitarian services provided to asylum seekers on Nauru and Manus once a $74 million contract held by the Salvation Army expires next year.

Questioned at his weekly media briefing in Sydney on Friday, Mr Morrison said a range of contracts for provision of services to offshore processing centres would expire soon and were "in the process of being determined with a view to improving our operational effectiveness at all of those centres".

He repeated claims of a $1.2 billion blow-out in the cost off-shore processing, blaming it on under-provision by his Labor predecessors.

"They clearly didn't have their heart in it because they clearly didn't put the dollars into it," he said.

He said he was not surprised by a report released by Amnesty International this week heavily criticising conditions on Manus Island, because this was to be "anticipated from groups or politicians or others who have long opposed the policy of offshore processing".

But he said the government would respond to "practical observations that can be verified that would improve the operations of these centres".

He denied there were restrictions on the amount of water asylum seekers could receive on Manus, or that treatment of those living in the camp amounted to torture.

Mr Morrison also denied reports that detainees suspected of homosexual activity on Manus were being automatically reported by Immigration staff to local police, though he added that "service providers provide clear advice to transferees on the relevant laws of Papua New Guinea".

"The department is unaware of any claims or declarations of homosexuality or any reports of homosexuality being investigated by police at the centre," he said.

During the so-called operational section of the briefing, the military head of Operation Sovereign Borders, Major General Angus Campbell, made a point of quashing what he said were rumours being fanned by people smugglers that the government was going to change its stance on asylum seekers arriving by boat.

Saying he wanted his message heard directly by those in transit countries, General Campbell turned mid-conference to Mr Morrison to ask him pointedly whether the government was considering any change in policy.

"Absolutely not," Mr Morrison said.

General Campbell sidestepped questions about the effects of continuing tensions between Jakarta and Canberra on combined efforts to defeat people smugglers, saying "those are issues at the moment for government-to-government discussions".

General Campbell said there had been two arrests on Thursday in relation to people-smuggling.

One, a 28-year-old Iranian, was arrested in Werribee, Melbourne, charged with aggravated people smuggling in relation to a vessel that capsized en route to Christmas Island on March 25.

The second man, a 25-year-old Indonesian, was arrested at Villawood in Sydney, charged over his role in crewing a boat that had capsized in August, with the suspected loss of five people whose bodies were never recovered.