Swedish prosecutors on Friday offered to question WikiLeaks founder Julian Assange in London, potentially unlocking a stalemate in an almost five-year-old investigation into alleged sex crimes.

Prosecutors had previously refused to travel to London, where Assange has taken refuge at the Ecuadorean embassy. Lead prosecutor Marianne Ny explained the change in position by saying some of the crimes Assange is accused of will reach their statute of limitations in August.

"My view has always been that to perform an interview with him at the Ecuadorean embassy in London would lower the quality of the interview, and that he would need to be present in Sweden in any case should there be a trial in the future," Ny said in a statement.

"Now that time is of the essence, I have viewed it therefore necessary to accept such deficiencies in the investigation and likewise take the risk that the interview does not move the case forward," Ny said.

She said she had made a request to Assange's legal team on Friday to interview him in London and to have a sample of his DNA taken with a swab.

One of Assange's defense lawyers, Per Samuelson, welcomed the move and said Assange would likely accept the offer after reviewing it in detail. He said he had spoken to Assange early Friday.

"This is something we've demanded for over four years," Samuelson told The Associated Press. "Julian Assange wants to be interviewed so he can be exonerated. So of course we welcome this."

Assange has not been formally indicted in Sweden, but he is wanted for questioning over allegations of sexual misconduct and rape involving two women he met during a visit to the Scandinavian country in 2010. He denies the allegations.

Assange has been in the Ecuadorean embassy since June 19, 2012.

He has said he has no intention of going to Sweden because he has no guarantees he wouldn't subsequently be sent to the U.S., where an investigation into WikiLeaks' dissemination of hundreds of thousands of classified U.S. documents remains live.

Ny has dismissed claims of any U.S. involvement in the Swedish investigation.