London, May 29 (IANS): Dubai-based firm Abraaj Group founder Arif Naqvi has been released on bail after paying £15 million -- the largest-ever security -- in the UK's judicial history.

Naqvi, the Pakistani man behind the world's largest private equity insolvency case, was arrested on April 10 at London's Heathrow Airport on behalf of the US authorities for defrauding US investors, including the Bill & Melinda Gates Foundation.

"He has been released from Wandsworth Prison after £15 million in cash was deposited with the court - which took over three weeks to raise since the decision granting him bail in early May," reported Geo News on Wednesday. Naqvi's bail application was also supported by three sureties, the report said.

Two of Naqvi's associates -- senior Abraaj executives Mustafa Abdel-Wadood in Manhattan and Sev Vettivetpillai in London -- are already out on bail, the report said.

Founded in 2002, Abraaj Group grew over the next decade to become the Middle East's biggest private equity fund and one of the world's most influential emerging-market investors, with stakes in health care, clean energy, lending and real estate across Africa, Asia, Latin America and Turkey.

However, last year Naqvi surrendered control of the firm after it was revealed that its main revenues hadn't covered operating costs for years.

Abraaj, which managed almost $14 billion, was forced into liquidation in June after several investors, including the Bill & Melinda Gates Foundation, commissioned an audit to investigate the alleged mismanagement of money in its healthcare fund.

Naqvi and Abdel-Wadood were charged with inflating the value of the firm's holdings and stealing hundreds of millions of dollars.