SYDNEY: Australian doctors mounted a legal challenge on Wednesday against laws which they say silence whistleblowers at immigration detention camps, after allegations of abuse at the controversial Pacific island centers. Doctors, lawyers and refugee advocates have criticized the offshore camps on Nauru and Papua New Guinea, alleging some asylum-seekers suffer from sexual abuse and mental health problems. Under Canberra’s tough immigration policy, asylum-seekers who try to reach Australia by boat are turned back or sent to the camps. They are barred from resettlement in Australia even if later found to be refugees. The conservative government brought in the secrecy provisions last year, making it a crime for anyone who works for the immigration department—including contractors such as medical professionals and aid workers—to disclose information they obtain on the job. The Doctors for Refugees, which is behind the legal challenge, argues that the laws breach the protection of freedom of political communication, and are therefore unconstitutional.