WikiLeaks founder Julian Assange says he has a trove of private documents on Rupert Murdoch and his News Corp empire and is prepared to release them in the event the whistle-blower website is taken down.

“If something happens to me or to WikiLeaks, 'insurance' files will be released,” he told The New Statesman. “There are 504 US embassy cables on one broadcasting organisation and there are cables on Murdoch and News Corp.”

The comments came a day after Assange told journalists in the UK that WikiLeaks planned to step up the publication of confidential US diplomatic cables following a lull in late December. The site will also move ahead with plans to publish tens of thousands of confidential documents depicting an “ecosystem of corruption” at Bank of America, CNBC reported.

Assange said WikiLeaks is mirrored on more than 2,000 websites.

Meanwhile, WikiLeaks supporter Jacob Appelbaum said in a series of tweets he was detained for about 30 minutes by US customs officials earlier this week upon his return from Iceland.

“I was detained, searched, and CPB did attempt to question me about the nature of my vacation upon landing in Seattle,” he wrote in one dispatch, in an apparent reference to the US Customs and Border Protection. “The CPB specifically wanted laptops and cell phones and were visibly unhappy when they discovered nothing of the sort. I did however have a few USB thumb drives with a copy of the Bill of Rights encoded into the block device. They were unable to copy it.” ®