Asylum seekers began hunger strikes last week at the Australian-run asylum-seeker processing centre, demanding the immigration department halt a scheduled January 22 transfer of 50 male detainees to temporary, insecure housing in Lorengau, the Manus capital.
Immigration Minister Peter Dutton has said the situation was volatile and urged those involved to refrain from self harm.
Refugee advocates said riot officers raided one compound in the early hours of Sunday, seizing ring leaders and placing them in isolation to stop the protest.
But a PNG government spokesman told AAP there was "no such incident" and that the raid did not happen.
Refugee Action Coalition spokesman Ian Rintoul said in a statement that men had to burrow under a perimeter fence to reach bottled water left outside the compound.
But a spokesperson for Mr Dutton said food and water continued to be available to the protesters, and most men at the centre received meals on Sunday.
Deputy Prime Minister Warren Truss could not confirm details on Sunday but said Mr Dutton would be seeking to do that.
"The flow of information is not always reliable," Mr Truss told reporters in Brisbane.
He reiterated the government message that people who arrived by boat without a visa would not be resettled in Australia.
"You won't be able to get your way into this country through some kind of illegal people smuggling operation or by, for that matter, put up an argument that somehow or other you are being badly treated now and therefore should be granted access to this country," Mr Truss said.
Opposition leader Bill Shorten says Australians are sick and tired of the culture of secrecy surrounding the asylum seeker processing centre there.
"Australians will normally give support to their government on tough matters - if people are told the truth," Mr Shorten told reporters in Melbourne on Sunday.
