Bank of America (BofA) has said that a "routine systems change" had caused its online banking service to go offline on Friday - not a Wikileaks attack.
According to media reports, a number of BofA's 29 million online banking customers were affected by the technical glitch, which occurred between 7am and 5pm Eastern Standard Time (EST).
Customers who were able to access their online bank accounts found that these were running slowly, with some struggling to transfer money between accounts. ATM and POS transactions were not affected.
"This has nothing to do with malware, Wikileaks or any type of attack," a spokesperson for the bank told Dow Jones Newswires.
BofA has reportedly assembled a team to produce a contingency plan in the event that Wikileaks follows through on its promise to release thousands of insider documents leaked to it.