Fairfax Media can also reveal: The federal government has issued new licences in the past six months to migration agents previously identified by the Immigration Department as having bribed employers to obtain fake work references for visa applicants. The department failed to investigate evidence of entrenched migration fraud involving 457 skilled worker visas and some of Australia's biggest infrastructure and mining projects. The fraud involves a large multinational contractor, Murphy Pipe & Civil, which has worked on the Queensland Curtis liquefied natural gas project and Western Australia's Sino Iron project. Leaked confidential company documents, along with statements from sources with detailed knowledge of the company's internal workings, have revealed how it has sponsored many Irish workers as ''project administrators'' or in other skilled roles, but employed them as labourers, machine operators and storemen.

Despite being tipped off last year, the Immigration Department failed to thoroughly investigate the company or interview a key whistleblower. The whistleblower claimed in a statutory declaration that the firm was ''constantly in breach of immigration laws'' by sponsoring unskilled Irish workers when unskilled workers ''could have been sourced locally''. MPC has denied the claims. The revelations come after Immigration Minister Scott Morrison demanded an urgent report from his department about allegations of widespread visa fraud and migration crime uncovered by a Fairfax Media investigation. Mr Morrison said on Thursday he was as serious about stopping visa fraud as he was about stopping the boats, and conceded that fraud in Australia's visa program could be costing Australians jobs. The allegations, based on hundreds of pages of leaked departmental documents obtained and published online by Fairfax Media, show widespread visa-rorting and migration rackets are operating in Australia, with some having links to terrorism and organised crime. Mr Morrison said the ''serious allegations'' revealed by Fairfax Media had occurred under the previous Labor government, while stressing that the integrity of Australia's visa and migration programs was ''incredibly important''.

The fresh revelations are likely to increase pressure on the Immigration Department and force the government to consider placing it under the jurisdiction of the national corruption watchdog, the Australian Commission for Law Enforcement Integrity. In an extraordinary twist, the department's latest annual report cites its role in uncovering the migration racket linked to Ms Ajjan to highlight its success in combating migration crime. But the annual report omits any mention of the role of its own official in what is described as among the ''the most sophisticated cases of organised migration fraud'' ever detected by the department. Secret departmental briefings obtained by Fairfax Media show that investigators believe Ms Ajjan should be charged with dealing ''with proceeds of crime of a value exceeding $100,000'' an ''offence [that] carries a maximum of 20 years' imprisonment''. ''Given the transfer of funds outside of Australia are suspected to have been proceeds of crime, national investigations are proposing charges against all three suspects, including the former DIAC officer [Ms Ajjan],'' investigators wrote.

The leaked files indicate that S and S Migration, a migration firm run by Mr Ajjan and Mr Sodhani, used stolen departmental stamps and equipment as part of a scam in which hundreds of overseas workers and students paid large sums to obtain visas to which they were not entitled. Fairfax Media has confirmed that the Immigration Department failed to implement basic measures, including seizing passports for analysis or ensuring a criminal charge could be quickly laid, to deal with the clear risk that the Ajjans and Mr Sodhani would flee Australia in the days after they were raided. One experienced police investigator told Fairfax Media that upon finding almost $500,000 in cash as well as equipment stolen from the department in the raid on the Ajjans' house, the pair could have been quickly charged with offences relating to money laundering, fraud or theft. Leaked files reveal that during the raid, immigration agents found $468,675 and a migration forgery operation, complete with several official departmental stamps and more than 1300 folders linked to general skilled migration claims ''with suspected false statements''. The files also show Ms Ajjan ''refused to comment on why or how'' the stolen Immigration Department equipment was ''found in their [the Ajjans'] possession''. Investigators also recovered a departmental visitor's pass.

In the days after the raid, Ms Ajjan called the Immigration Department to say she would be taking time off work. Ms Ajjan and her husband wired $1.2 million to India, including one transfer of $543,000 made by Ms Ajjan. ''The AFP is trying to repatriate these funds as part of proceeds of crime referral, but given the funds were sent to India, this may be difficult to achieve,'' a leaked file states. Loading With John Garnaut Follow us on Twitter