About 160 asylum seekers at Sydney' s Villawood detention center are staging a hunger strike following the death of an Iraqi detainee, refugee advocates said on Tuesday.

Ahmad Al Eqabi, believed to be in his 40s, was found in a shower cubicle about 12:40 a.m. (local time) on Tuesday, according to witnesses.

He was taken to Liverpool Hospital and pronounced dead.

The Immigration Department denied a hunger strike was under way following the incident but the Refugee Action Coalition (RAC) and the Sydney-based refugee advocacy group Social Justice Network ( SJN) told Australian Associated Press(AAP) that 160 Iraqis, Iranians, Afghans and Sri Lankans were taking part.

"They want answers about detention, they want answers about the man's death, they want answers about their own cases," RAC's Ian Rintoul said, adding that all boat people detained in the area known as Stage 3 were protesting.

Speaking from outside Villawood on Tuesday afternoon, Rintoul said the protesting detainees were chanting "we want freedom" in English, while others had told him via telephone they were "tired of waiting", with some being held for 18 months.

SJN's Jamal Daoud said Al Eqabi was suffering depression and had tried to take his own life several times in the past few months. His asylum claims had been rejected twice.

Rintoul said it was believed the man had a wife and four children and had been in detention, on Christmas Island and in Villawood, for more than a year.

The Department of Immigration confirmed the death but says it will not release any details about the man until his next of kin overseas have been informed.

When asked how many detainees were taking part in the hunger strike, believed to have begun on Tuesday morning, a department spokesman replied "none".

"They have been observed eating and drinking," he said.