Julian Assange will be interviewed inside the Ecuadorian Embassy on 14 November over allegations he sexually assaulted two women in 2010.
The Swedish Prosecution Authority said that Ecuador has granted a request for legal assistance and for an interview to be conducted by an Ecuadorian prosecutor, with Swedish prosecutor Ingrid Isgren and Swedish police also being present.
The WikiLeaks founder will be asked to provide a DNA sample as part of the questioning. The Swedish Prosecution Authority said in statement: "The results of the interview will later be reported from Ecuador to the Swedish prosecutors in a written statement.
"Ingrid Isgren will not give interviews during her stay in London. As the investigation is ongoing, it is subject to confidentiality. This confidentiality also applies according to Ecuadorian legislation for the investigative measures conducted at the embassy."
Assange has been holed up inside the building since 2012 under political asylum in a bid to avoid being extradited to Sweden to face sexual assault charges. He believes that once he is in Sweden, he will be extradited again to the US where he could face espionage charges following the leaking of thousands of classified documents on his WikiLeaks website.
A Swedish court previously rejected an appeal from Assange to have his arrest warrant over sexual assault allegations revoked. Assange denies all the allegations against him.