In an email to Reuters, Daniel Domscheit-Berg, who last year was fired by Assange as WikiLeaks' co-spokesman, confirmed that he had destroyed "roundabout" 3,000 submissions WikiLeaks received related to Bank of America.
Domscheit-Berg said that he had decided to destroy the material "in the interest of the security of sources." In the past he had alleged that the source-protection system used by WikiLeaks under Assange's stewardship was inadequate.
Domscheit-Berg, who has been working on the creation of a rival to WikiLeaks called OpenLeaks, said that the Bank of America material which he destroyed was sent to WikiLeaks between January 2010 and September 2010. In September 2010 Assange ousted Domscheit-Berg, who then used the pseudonym "Daniel Schmitt", as one of WikiLeaks' principal frontmen.
Domscheit-Berg said that the 3,000 Bank of America submissions that he destroyed consisted of "about 10-15% documents and the rest random junk people sent in." He did not characterize the destroyed material's content further.
But Domscheit-Berg also said that he did not destroy Bank of America material obtained by WikiLeaks before last year. He said that Assange first claimed to have obtained leaks from inside Bank of America in October 2009. Domscheit-Berg said he never had control over such files and did not destroy them.
Larry Di Rita, a Bank of America spokesman, said: "We don't know what they claim to have had, and we have no comment on what they allegedly may have destroyed."
The destruction of the documents could provide a small amount of relief to Bank of America investors. The bank's stock dropped 3 percent in November amid fears the bank could be the target of WikiLeaks' next document release. In recent weeks investors have pummeled Bank of America's stock on fears it may need to raise outside capital to absorb losses.
Assange did not immediately respond to an email requesting comment. However, in a flurry of messages posted on its Twitter feed over the weekend, WikiLeaks said that it could confirm that the data Domscheit-Berg claimed to have destroyed "included five gigabytes from the Bank of America."
The WikiLeaks Twitter feed, which Assange is believed to control personally, also said that Domscheit-Berg had destroyed a copy of "the entire US no-fly list," "US intercept arrangements for over a hundred internet companies," and leaks from inside "around 20 neo-Nazi organizations."
It is unclear from the statements by WikiLeaks and Domscheit-Berg whether WikiLeaks and Assange still have any Bank of America files under their control.
In an October 2009 interview with the Computerworld website, Assange said that he was "sitting on 5GB from Bank of America, one of the executive's hard drives." Five gigabytes is precisely the size of the data cache that the WikiLeaks Twitter feed now claims that Domscheit-Berg destroyed.
However, Domscheit-Berg told Reuters he only destroyed material which WikiLeaks received months after Assange gave the interview to Computerworld. But he also said that when he and Assange were still collaborators, Assange once accused him of stealing the pre-October 2009 Bank of America material.
Domscheit-Berg said that because WikiLeaks' pre-2010 system for receiving data was poorly built, it was, in his view, possible that Assange no longer had any Bank of America material under his control.
Assange at one point claimed publicly that WikiLeaks had material which could "take down a bank or two".