A Department of Immigration spokeswoman confirmed that a ''series of incidents'' led to Mr Doost having his community residency revoked in September last year. Mr Doost continues to be involved in violent incidents in Sydney's Villawood detention centre, according to the whistleblower, a manager in the department. In another incident, a detainee in Melbourne was released into the community only two weeks after threatening self-harm and to kill staff in a roof-top protest, the whistleblower told Fairfax Media. ''This person could be your next door neighbour,'' he said. The whistleblower, who has worked in detention centres in three different locations, said the department has a target of 2000 asylum seekers being released into the community on bridging visas every month.

''Normally this is done within two to three months of arrival and prior to the security/medical checks being properly completed,'' he said. ''This is against the advice of other government departments and is being done because the department doesn't want to be seen opening more centres . . . they would rather put the Australian public at risk than take the hit of opening new centres.'' The department spokeswoman said detainees were checked against alert lists before being moved into the community but declined to provide details about further security checks, citing operational reasons. ''The department ensures that initial security and identity checks are undertaken prior to moving clients into the community,'' she said. The spokeswoman said detainees undergo a thorough medical check upon arrival in Australia.

During question time on Thursday, the Coalition pursued the government over the allegations raised by the whistleblower. Manager of Opposition Business asked Prime Minister Julia Gillard if Mr Doost's case and that of the man involved in the rooftop protest would be included in the inquiry announced by the government on Wednesday. Ms Gillard said it was impossible for her to direct the inquiry as the Inspector-General of Intelligence and Security, Vivienne Thom, was independent. "Of course in line with being an independent office bearer, that is a matter for her," she told parliament. The Prime Minister accused the opposition of trying to raise fear in the community.

"Their source for questions in question time in the Australian Parliament is a newspaper clipping from an anonymous source ... they have no ability to check the veracity of what is claimed." The whistleblower said some of the most dangerous people in immigration detention are regularly taken to the movies, shops and religious places while department managers withhold information about the excursions from local police and other agencies ''because we don't want them communicating back to Canberra and it biting us''. ''I tell you right now that I am very concerned about this and would not take my family anywhere near this,'' he said. The department's spokeswoman said excursions were arranged to help detainees to ''understand the Australian community and to promote mental health issues'' and a security risk assessment was done for each person before they leave the centre. The whistleblower said the immigration centre network was unravelling under the strain of new asylum seeker arrivals.

In September 2009 the immigration detention network had less than 800 people in five centres while there are now 10,000 in 22 centres. In April alone 48 boats arrived carrying 3300 people. ''The main thing I want to explore here is the hopelessness of the immigration detention network and how it's beginning to be a real threat towards Australia and Australians,'' said the man, who insisted he is not a disgruntled employee but a pragmatist with strong views about what is right and wrong. The whistleblower said serious criminals and others who have military and police training overseas are living in centres surrounded by ''pool fences'' and staffed by welfare officers. ''These people are very dangerous but the department thinks talking to them will solve the risk,'' he said.

The whistleblower said dangerous detainees could easily escape and ''the only thing stopping them is a quick pathway to a bridging visa''. He said mentally ill detainees continually self-harm by slashing themselves and swallowing razor blades and staff were regularly assaulted. An officer from the security company Serco, which has $1.8 billion contract with the department, was seriously assaulted last week, he said. The whistleblower said he was speaking out because the department has created a ''toxic environment'' where people blamed each other and outsiders such as staff from Serco and there was no real leadership. ''Just because you have run a passport office . . . doesn't mean you can run a high security detention centre,'' he said.

''I am not going to name names or point the finger at specific people within the department but more so the culture, and the failures to run the network how it should be run . . . I know it is highly political but we have ex-child care workers running high security detention centres and other officers with little experience developing policies and procedures at a time that is so unprecedented no-one knows what is going to happen tomorrow let alone next month.'' He added: ''If things go wrong we can just blame other stakeholders as they are easy targets.'' Last week a whistleblower employee of Serco said the British-based company routinely underplayed the risks of guarding asylum seekers and prisoners to cut costs. Serco denied the claim. with Judith Ireland Do you know more? Contact Lindsay Murodch, email: lmurdoch@fairfaxmedia.com.au