Online payment service PayPal said it has suspended the WikiLeaks' account that the organization used to collect donations.
U.S.-based PayPal said in a statement that WikiLeaks, which this week released thousands of secret U.S. diplomatic cables, had violated its policy.
A posting on WikiLeaks' Twitter page said "PayPal bans WikiLeaks after US government pressure."
A statement on the PayPal site said: "PayPal has permanently restricted the account used by WikiLeaks due to a violation of the PayPal Acceptable Use Policy, which states that our payment service cannot be used for any activities that encourage, promote, facilitate or instruct others to engage in illegal activity. We've notified the account holder of this action."
PayPal is one of several ways that WikiLeaks takes in donations to finance its operations.
On Friday, WikiLeaks directed readers to a web address in Switzerland after two U.S. Internet providers dropped it in the space of two days.
The Internet publisher directed users to www.wikileaks.ch after the wikileaks.org site on which it had published classified U.S. government information vanished from view for about six hours.