An asylum seeker in Australia's immigration detention network on Manus Island has died, with local police suggesting the man may have taken his own life.

Hamed Shamshiripour, a 31-year-old Iranian with a history of mental illness, was found dead on Monday near the Refugee Transit Centre in East Lorengau. He was the fifth man to die under Australia's supervision on Manus Island.

Manus provincial police commander David Yapu said a crime scene had been established but was unable to provide further details on Monday.

The precise time and location of the death are unclear but it is understood Mr Shamshiripour had been ordinarily living at the transit centre.