WikiLeaks founder Julian Assange said in an interview published yesterday he believed the Pentagon could be behind a rape allegation against him that was swiftly dropped by Swedish authorities.

His comments came as prosecutors justified their treatment of the 39-year-old Australian, whose whistleblowing website is embroiled in a row with Washington over the publication of secret Afghan war documents.

The Aftonbladet newspaper quoted Mr Assange as saying he did not know who was “hiding behind” the rape claim, which prompted prosecutors to issue a warrant for his arrest on Friday but which was cancelled the following day.

“But we have been warned that for instance the Pentagon will use dirty tricks to destroy us. I have furthermore been warned about set-up sex traps,” he said, in a translation of comments published in Swedish.

The former computer hacker described the allegations as “shocking” and said he had “never, neither in Sweden nor in any other country, had sex with someone in a way which wasn’t completely voluntary on both sides.”

Mr Assange told Aftonbladet – for which he last week agreed to write a regular column – that his enemies would still use the claims to damage WikiLeaks despite the lifting of the warrant.

The website is set to publish 15,000 more secret papers about the war in Afghanistan in the coming weeks, having recently released nearly 77,000 papers and sparking charges that it had endangered the lives of informants and others.

“I know from experience that WikiLeaks’ enemies continue to trumpet things even after they have been denied,” Mr Assange said.

He refused to give more details about the two women whose claims sparked the furore, saying that it would impinge on their privacy.

Pentagon Press Secretary Geoff Morrell said any allegation of dirty tricks was “absurd”.

Sweden’s prosecution service said on Saturday that Mr Assange was now “not suspected of rape” and was no longer wanted for questioning on the allegation, but added that an investigation into a separate molestation charge remained open.

He had been in Stockholm earlier this month giving a press conference on the upcoming release of the last batch of Afghanistan documents, but he generally remains on the move around the world staying with supporters.

He told Aftonbladet he was currently at a friend’s summerhouse in northern Sweden. As the furore over the arrest warrant grew, the Swedish prosecutor’s office issued a statement on Sunday defending its actions.

It said that chief prosecutor Eva Finne, who was responsible for withdrawing the arrest warrant, had “more information available to decide on Saturday than the duty prosecutor on Friday evening”.