Julian Assange, the founder of the whistleblower website Wikileaks, has had his passport confiscated by immigration officials when he arrived at Melbourne Airport last week.

According to reports, the passport was returned to him after about 15 minutes, but Assange was told by authorities that his passport was going to be cancelled because it was looking worn.

But Assange told the Australian current affairs programme Dateline that he has since received a letter from the Australian Communication Minister Steven Conroy's office stating that the the Australian Federal Police (AFP) has been asked to investigate the recent disclosure on Wikileaks of the Australian government's blacklist of banned websites.

Last year Wikileaks published the confidential list of websites the Australian government is preparing to block under its proposed internet filter, which included links to YouTube clips, sites on euthanasia and pornography.

Immigration officials reportedly told Australian newspaper The Age that Assange's passport is classified as 'normal' on the immigration database, meaning the Wikileaks founder can travel freely on it.

Assange said half an hour after his passport was returned to him, an AFP officer searched one of his bags and questioned him about a previous criminal record relating to computer hacking offences from when he was a teenager.

However, The Age reports that an AFP spokeswoman said the federal police had dropped the case earlier this year because it was 'not in our jurisdiction'.

Wikileaks, which publishes anonymously sourced confidential documents from governments and corporations, was launched in January 2007. Last month Wikileaks published classified US military footage of an American attack helicopter gunning down Iraqi civilians in 2007.

Assange, who is Australian but does not have an official home base and travels every six weeks, told Dateline that Australia is one of several countries where he feels unsafe.

This story, "Wikileak Founder's Passport Confiscated" was originally published by Computerworld UK .