Swedish prosecutors have offered to question Julian Assange in London over sexual assault allegations against him.

The WikiLeaks founder faces an arrest warrant in Sweden over claims he sexually assaulted two women in 2010.

Prosecutors had previously refused to travel to London, where Mr Assange has claimed asylum at Ecuador's embassy.

But lead prosecutor Marianne Ny, explaining their new stance, said some of the crimes Mr 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," Ms Ny said.

"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."

One of Mr Assange's lawyers, Per Samuelson, welcomed the offer. He said Mr Assange would likely accept the offer after reviewing it in detail.

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

The 43-year-old Australian took refuge at the embassy in June 2012 after failing to stop proceedings to extradite him to Sweden.

He faces arrest if he leaves the embassy and has been under continual surveillance with police stationed outside the building.

Mr Assange said he did not want to go to Sweden as he feared he would then be extradited again to the United States for questioning over the publication by WikiLeaks of confidential information.

He denies the sexual assault allegations.

Last month, a police official said they are reviewing the surveillance operation outside the embassy.

Deputy prime minister Nick Clegg revealed the cost of the surveillance operation outside the Ecuadorian Embassy in London had reached around £10m (around €13.4m).

Metropolitan Police Commissioner Sir Bernard Hogan-Howe told LBC radio: "We are reviewing the way forward there.

"There is no doubt it's a drain - we'll look to see what other opportunities we have, how we can do that in the future. It's sucking our resources."

Mr Assange spoke to Sean Moncrieff last year about life in the embassy: