A coroner has found authorities failed in their duty of care to three men who committed suicide at Sydney's Villawood Immigration Detention Centre.

British citizen David Saunders, Fijian man Josefa Rauluni and Iraqi Ahmad Al Akabi all died at the centre between September and December last year.

New South Wales Coroner Mary Jerram has criticised the Department of Immigration and Citizenship, Villawood's private operator Serco and health services contractor IHMS (International Health and Medical Services).

"In all three deaths, some of the actions of some of the staff were careless, ignorant or both, and communications were sadly lacking," Ms Jerram said.

"It has to be said that none of the three authorities escape criticism for the manner in which that duty was fulfilled in caring for the inmates at Villawood, at least in the last months of 2010."

Ms Jerram has found staff often ignored policies and procedures to deal with potential cases of self-harm.

The coroner said continuity and communication at the centre were lacking.

"It is surely stating the obvious to observe that persons detained in immigration detention centres must, by the nature of their various situations, be at much greater risk of suicide than the general community," she said.

Fijian man Josefa Rauluni died in September last year. ( Lateline )

"Those responsible for detainees owe a greater than normal duty of care to those persons regarding their health and wellbeing."

Of the three suicides Ms Jerram said Ahmad Al Akabi's was the most foreseeable and therefore theoretically preventable.

"IHMS must be said to have failed in its duty of care to Ahmed Al Akabi. Its system was under-resourced and under stress," Ms Jerram said.

"The seriousness of his mental state was not detected, documentation practices were extremely poor and there was a sad lack of continuity in his clinical care."

Ms Jerram has made recommendations to Immigration Minister Chris Bowen, Serco and IHMS to revise procedures for detainee management and removal.

She says greater collaboration is needed between the agencies in developing policy guidelines.

"When Government chooses to maintain a detention system, it carries a heavy responsibility," she said.

"Similarly a company which contracts to shoulder a large part of that responsibility is under a major obligation to fulfil its contract, both to Government and to those in its care.

"For the reasons I have given, it cannot be said that either DIAC nor Serco met those responsibilities in full."