WikiLeaks has released 30 hours of secret audiotapes and transcripts purporting to implicate appointees of the Obama and George W. Bush administrations in a multibillion-dollar corruption scandal involving a federal disability program.

The whistleblower organization says that the conversations, which took place between 2013 and 2014, reveal that federal officials from both administrations misappropriated funds in a government program called AbilityOne - the largest employment program for disabled people in the U.S.

Each year, AbilityOne awards some $2.3 billion in government contracts to companies in which at least 75 percent of work is performed by disabled people as a way to get disabled people into the workforce. Most of the money is distributed by the non-profit SourceAmerica, reports The Telegraph.

But the WikiLeaks tapes allegedly reveal that more than half of the $2.3 billion went to defense contractors and other major corporations that did not employ enough disabled people to qualify for the federal money, including the Department of Defense and contractors like Lockheed Martin, Northrup Grumman and Boeing.

"It is alleged that nearly half of the $2.3 billion a year does not go to the severely disabled, but is rorted by pushing the money to corruptly favored placement organizations that recruit the able bodied or the mildly disabled instead of the mandated 75% severely disabled," WikiLeaks said. "The result is billions in tax payer funded labour subsidies and increased profits for the placement organizations."

WikiLeaks said the tapes include conversations between the lead counsel of SourceAmerica, Jean Robinson, and Ruben Lopez, CEO of Bona Fide Conglomerate Inc., one of the placement organizations.

Ten officials appointed by President Obama and three appointed by former President Bush were allegedly involved in the misappropriations.

The WikiLeaks documents support claims that emerged in July, when critics first accused officials of awarding contracts to companies that did not employee the necessary number of disabled employees to quality for the federal money, according to The International Business Times.

SourceAmerica released a statement earlier this year denying those claims: "SourceAmerica conducts its business with the utmost integrity and complies with all federal and state requirements, including those related to the administration of the AbilityOne Program. The allegations being made against SourceAmerica are simply without merit.

"SourceAmerica is defending itself against these unfounded allegations, many of which are related to ongoing litigation brought forth by a very small number of individuals, and we anticipate a favourable resolution of these lawsuits."