WikiLeaks founder Julian Assange has reportedly told media contacts that he has a large cache of files on the US's detention facility in Guantanamo Bay.

Reuters quotes an unnamed "contact" who says Assange has "got the personal files of every prisoner in Gitmo."

People familiar with Assange's dealings with the media said they had no indication he had already given journalists access to the Guantanamo material. In the past, large document dumps by WikiLeaks were made available initially to a small group of media.

Several U.S. government sources said there was concern Assange's material could include highly sensitive "threat assessments" by U.S. intelligence agencies gauging the likelihood that specific inmates would return to militant activities if set free.

They could further embarrass the U.S. government if they show that detainees deemed likely to return to terrorism were released and subsequently involved in anti-U.S. violence.

The claim comes as the Obama administration's efforts to close Guantanamo Bay hit a major roadblock. On Wednesday, the House passed a bill barring Guantanamo prisoners from US soil.

Claims and rumors about WikiLeaks' next move have been flying since the site began releasing US State Department cables late last month.

As Raw Story reported, WikiLeaks is believed to hold a cache of data about a "major American bank."

Some Wall Street insiders believe the bank in question to be Bank of America. They say the documents could have to do with Countrywide Financial, the mortgage company BofA bought in 2008. The documents may show widespread mortgage fraud at the institution.