lara Bailon, 36, suffering from Larsen syndrome arrives to take part in the disability pride parade in New York, July 12, 2015. Reuters WikiLeaks has released 30 hours of audio recordings related to a disability program at the center of what it says is a multi-billion-dollar corruption scandal.

The whistleblowing organization published the secret tapes and transcripts of conversations that took place between 2013 and 2014 , exposing details of the federal investigation into the non-profit agency SourceAmerica.

The recordings appear to provide evidence of fraud within the administrations of George Bush and Barack Obama, with appointees to both presidents allegedly misappropriating funds in a government programme called AbilityOne.

The programme is the largest employment programme for disabled people in the US, funneling $2.3 billion (£1.5 billion) a year through SourceAmerica to more than 1,000 designated partner organizations.

The tapes, which are still being analyzed by IBTimes UK, allegedly show that almost half of the funds go to defence contractors and major corporations rather than disabled people.

"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 organisations that recruit the able bodied or the mildly disabled instead of the mandated 75% severely disabled," WikiLeaks said in a statement released with the recordings.

"The result is billions in taxpayer-funded Labour subsidies and increased profits for the placement organisations."

In a statement released earlier this year, when allegations about corruption emerged, SourceAmerica said: "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 favorable resolution of these lawsuits."

SourceAmerica has previously recognized one instance where a non-profit agency was found to have falsified records, but it claims to have taken immediate action to remove that agency from the program. The organisation is yet to comment on the most recent revelations.