Australia's co-operation with Sri Lanka has been seriously questioned in a new report by international human rights lawyers, who say that it is deeply flawed and jeopardises asylum seekers' attempts to seek safety.

The report by the Human Rights Law Centre condemns Australia's ''stopping the boats'' policy in Sri Lanka where asylum seekers are often sent back to Sri Lankan militaries, the authorities they are fleeing from.

Negombo Prison, near Sri Lanka's international airport, where most of the Sri Lankans whose asylum seeker claims in Australia have been rejected are sent. Credit:Ben Doherty

The Abbott government last year gave the Sri Lankan navy two Bay-class patrol boats, recently retired from surveillance service in Australia, to intercept asylum-seeker boats before they leave Sri Lankan waters.

Australia continually claims that no asylum seekers sent back to Sri Lanka have been harmed, but documents obtained by a freedom of information request established at least one instance where Australia received a complaint that a man had been "severely tortured" upon his return from an Australian-run detention centre, the report said.