A Swedish tabloid reported yesterday that an arrest warrant has been issued for Wikileaks found­er Julian Assange on suspicion of rape, and officials said they could confirm "media reports".

The prosecutor's office in Stockholm issued a brief statement saying it "confirms media reports that a foreign citizen has been arrested in absentia" but did not name Assange.

"The arrest refers to two separate events, one complaint of molestation and one complaint of rape," the statement said. "The person is arrested in absentia, as there is a risk that he could obstruct the investigation," it said.

Tabloid Expressen said prosecutor Maria Haljebo Kjellstrand confirmed that Assange, who is an Australian citizen, was the person sought on the warrant. The prosecutor's office said all information related to the case would be posted on its website.

"We were warned to expect 'dirty tricks'. Now we have the first one," Wikileaks said on its Twitter page.

"Expressen is a tabloid. No one here has been contacted by Swedish police. Needless to say this will prove hugely distracting," it said in another tweet.

Assange was in Sweden last week partly to apply for a publishing certificate to make sure the website, which has servers in Sweden, can take full advantage of Swedish laws protecting whistleblowers.

He also spoke at a seminar hosted by the Christian faction of the opposition Social Democratic Party and announced he would write bimonthly columns for a left-wing Swedish newspaper.

Wikileaks angered American intelligence services last month by publishing thousands of pages of classified documents relating to the war in Afghanistan. The site was accused of endangering the lives of Afghan informants by its actions.