Bank of America follows Visa, MasterCard and PayPal in cutting off WikiLeaks payments processing, as the site continues to publish thousands of highly embarrassing diplomatic US government cables.

In a brief statement, the bank said it acted "based upon our reasonable belief that WikiLeaks may be engaged in activities that are, among other things, inconsistent with our internal policies for processing payments."

Bank of America is understood to be the subject of a future WikiLeaks expose, with tens of thousands of internal documents set to be released early next year.

In an interview with Forbes magazine last month, WikiLeaks founder Julian Assange claimed the documents would reveal an eco-system of corruption in US banking on a similar scale to that witnessed at Enron.

Bank of America is understood to have assembled an emergency 'war room' in anticipation of the impending release.

WikiLeaks responded to the latest assualt by corporate America on the site with a message on Twitter, urging "all people who love freedom close out their accounts at Bank of America".

The Website also called for businesses to "place your funds somewhere safer", in a veiled hint about the likely impact of its forthcoming disclosures.