He was threatened with beheading by the Taliban after immigration officials leaked his private details online, and now asylum seeker Nadir Sadiqi fears he will be sent home to certain death in Afghanistan.

Mr Sadiqi was among 10,000 asylum seekers – about one third of those held in Australia at the time - whose identities were revealed in a massive data breach by the Department of Immigration and Border Protection in February last year.

Their names, nationalities, arrival dates and other details were published on the department's website in a serious breach of privacy.

It raised grave concerns that those who had fled dangerous situations were exposed to an even greater risk.