In yet another blow to WikiLeaks, Visa Europe today said it has begun suspending payments to the whistle-blowing website ahead of carrying out an investigation into the organisation.

Visa is the latest company to cut its links with Wikileaks, following online payment firm PayPal. It cut off the account used to collect donations, saying the website is engaged in illegal activity.

Wikileaks relies on online donations to fund its operations, which will now not be possible using Visa cards.

A spokeswoman for Visa Europe said its investigation would determine the nature of Wikileaks' business, and "whether it contravenes Visa operating rules".

Visa Europe could not suspend payments to Wikileaks immediately, and that the process took a certain amount of time, she was quoted as saying by BBC.

Meanwhile, Mastercard said in its statement that it was "in the process of working to suspend the acceptance of Mastercard cards on Wikileaks until the situation is resolved".

The announcements also came as WikiLeaks is struggling to keep its website accessible after service providers such as Amazon dropped contracts, and governments and hackers continued to hound the organisation.

Wikileaks' founder Julian Assange was arrested by police in London today.

Assange, whose website has published secret documents, is wanted in Sweden on sexual assault allegations.

Swiss authorities closed Assange's new Swiss bank account yesterday.

WikiLeaks also is under legal pressure in several countries, including the US.