Detainee was held for six months in an ‘observation room’ where he was allowed limited contact with others

Hundreds of asylum seekers at Villawood detention centre have been placed in solitary confinement for days at a time at the direction of staff without medical qualifications.

A Guardian Australia investigation has revealed extensive use of “observation rooms” at the centre in western Sydney for periods that frequently exceed 24 hours.

Incident logs obtained under freedom of information laws show that there have been more than 800 “uses of observation rooms” that exceed 24 hours at the Villawood detention facility between January 2010 and February 2014.

Some people have been held in isolation from the rest of the detainee population for much longer periods of time.

A separate report shows that one asylum seeker was held for six months in one of the Annex observation rooms in Villawood, where he was allowed limited contact with the rest of the population.

The logs follow reports of renewed concerns about the use of solitary confinement on Manus Island, after Guardian Australia and Fairfax Media reported on the use of a new compound called “Chauka” where asylum seekers are now being held in isolation.

The use of solitary confinement or isolation in mental health facilities, detention centres and prisons, also known as “seclusion”, has been strongly condemned by health practitioners in Australia and abroad due to the serious risks it poses to mental health when used for long periods.

Greens senator Sarah Hanson-Young said: “Isolation is a crude and inappropriate form of punishment that puts people’s mental health at risk.

“Following the disturbing revelations of an active isolation chamber on Manus Island, these documents show that the practice is also common in Australia.

“I’ve seen the ‘observation’ rooms in Villawood and the fact that refugees are being locked in there, sometimes for over a week, is extremely concerning.”

The reasons for the confinement vary. Some asylum seekers are placed in the rooms to prevent acts of self-harm, while some are placed for “anti-social behaviour” or following altercations with staff or other asylum seekers. Others are placed there when they are deemed to be flight risks shortly before a forced deportation.

Other logs are even vaguer, with some attributing their relocation “due to intelligence information received”, with no clear indication of the reasons for confinement.

Villawood’s observation rooms were known as the “Annex”, although there have been some changes to the facility since an upgrade this year. There were three small observation rooms as well as a number of other dormitories where detainees are also kept in isolation. The Murray unit also had a separate observation room that the Australian Human Rights Commission has previously described as “essentially prison cells”.

The placement of the asylum seekers is made on the authority of staff who are not required to have medical training.

The department’s policy manual, which dates to 2011, on the use of detention in restrictive environments shows that its regional managers, not medical staff, make decisions on whether a detainee can be held in isolation for more than 24 hours.

“They don’t have any medical qualifications,” said Louise Newman, director of the Monash University Centre for Developmental Psychiatry and Psychology. “You’re talking about bureaucrats making decisions about restrictive seclusion of people, which is very different. It’s a political process, it’s not a process of a health professional being asked if it’s in the person’s best interests or safe to use those sorts of practices.”

Hanson-Young said: “It’s alarming that no mental health professionals are involved when making the decision to send people to isolation.”

Minutes from a meeting of the Detention Health Advisory Group, which advised the immigration department and Serco on health matters in detention centres before being disbanded by the immigration minister in December 2013, also suggest that International Health and Medical Services (IHMS) staff only have an advisory role in the process.

The minutes state that Tony Hassall, the chief operating officer of Serco, remarked in a February 2012 meeting that “the process for placing a person in restrictive detention has a number of checks and balances, involving the initial referral, followed by an operational and health assessment, and then a decision by the regional manager regarding the placement”.

They add that “the health assessment by IHMS is not to ‘endorse’ the placement, but to advise of any health concerns and to consider any pre-existing vulnerabilities. In general, referrals for placement based on behavioural issues are identified by Serco and referrals based on clinical issues are identified by IHMS.”

The immigration minister, Scott Morrison, and Serco did not respond to questions about the use of the isolation rooms.