The request was filed with Assange's lawyer by the Swedish Director of Public Prosecutions, Marianne Ny , her office said Friday.
A Swedish court ordered Assange to be detained in November 2010 on suspicion of rape, sexual molestation and unlawful coercion. Since then, Swedish authorities have been trying to extradite Assange to Sweden.
Assange denies the allegations and, after exhausting his legal options to fight the extradition, took refuge in Ecuador's U.K. embassy in June 2012.
He fears that if he is forced to go to Sweden, he could eventually be extradited to the U.S. where he could be charged for publishing thousands of secret U.S. diplomatic cables on the WikiLeaks website.
The cache of U.S. cables for instance linked China to a 2009 hack of Google's computer systems. The hundreds of thousands of cables were leaked by Private First Class Bradley Manning (now Chelsea Manning), who had access to the Secure Internet Protocol Router Network (SIPRNet), a computer network used by the U.S. Department of Defense and the U.S. Department of State.
Manning was convicted for the leaks in July 2013 and sentenced to 35 years in prison. Assange, who published the cables, has been more successful at avoiding prosecution.
The Swedish prosecutors are now willing to go to London to beat the statute of limitations on some of the allegations from running out.
Ny said she would have preferred to interview Assange in Sweden, but would rather interview him in the Ecuadorean embassy than not at all.
If Assange agrees to the prosecutors' proposal, the prosecutor will submit a request for legal assistance to the British authorities to continue the investigation, and send a request to to the Ecuadorian authorities to perform an investigation in the London embassy.
Per Samuelson, Assange's lawyer, did not immediately respond to a request for comment.
Loek is Amsterdam Correspondent and covers online privacy, intellectual property, online payment issues as well as EU technology policy and regulation for the IDG News Service. Follow him on Twitter at @loekessers or email tips and comments to loek_essers@idg.com