WIKILEAKS founder Julian Assange is believed to have been tipped off more than seven months ago about Australian intelligence scrutiny of his whistleblowing activities.

Senior government ministers yesterday claimed to have no knowledge of co-operation between Australian intelligence agencies and the United States government concerning Assange after WikiLeaks began publishing thousands of secret documents leaked from the US Defence Department.

But sources within Wikileaks have told The Age that an Australian intelligence official privately warned Wikileaks on August 11 last year that Assange was the subject of inquiries by the Australian Security Intelligence Organisation, and that information relating to him and others associated with Wikileaks had been provided to the US in response to requests through intelligence liaison channels.

The Australian intelligence official is also claimed to have specifically warned that Assange could be at risk of ''dirty tricks'' from the US intelligence community, including the possibility of sexual entrapment.

The information is said to have been provided to WikiLeaks by means of a submission through the website's electronic ''drop box'' on the day Assange flew from London to Stockholm to speak on freedom of the press.