Assange told the BBC that one account of what happened in August -- the month at the centre of allegations against him -- was that the two women had panicked when they found out they had both slept with him and went to police who "bamboozled" them.
He insisted he was fighting a Swedish extradition warrant because he believes "no natural justice" would occur in Sweden.
"There are some serious problems with the Swedish prosecution," he said in an interview from the mansion of a wealthy supporter in eastern England where he must stay as part of his bail conditions.
Sweden wants Britain to extradite the 39-year-old Australian to face questioning over allegations from two women that he raped one of them and sexually assaulted the other in Stockholm in August.
Assange claimed that the Swedish authorities had asked that his Swedish lawyer be "gagged", adding that his offers to be interviewed by video link or by Swedish officials in Britain had been rejected.
"I don't need to be at the beck and call of people making allegations," he said.
"I don't need to go back to Sweden. The law says I... have certain rights, and these rights mean that I do not need to speak to random prosecutors around the world who simply want to have a chat, and won't do it in any other standard way."
He said that one account of what occurred in August was that after having discovered they had each had sex with him, they had got into a "tizzy", or a panic, about the possibility of sexually transmitted diseases.
As a result, he said, the women had gone to the police for advice "and then the police jumped in on this and bamboozled the women".
WikiLeaks has enraged Washington by releasing thousands of US diplomatic cables and US Vice President Joe Biden described Assange as a "hi-tech terrorist".
US officials are believed to be considering how to indict Assange for espionage.
In an interview with The Times on Tuesday, Assange compared WikiLeaks' "persecution" to that endured by Jews in the US in the 1950s.
Assange also confirmed that WikiLeaks was holding a vast amount of material about Bank of America which it intends to release early next year.
"We don't want the bank to suffer unless it's called for," Assange told The Times. "But if its management is operating in a responsive way there will be resignations," he said, without giving details about the material.
Shares in Bank of America have fallen amid speculation that it was a WikiLeaks target.