The top Swedish prosecutor pursuing sexual assault charges against Julian Assange has abruptly left the case and one of Mr Assange's accusers has sacked her lawyer. The turmoil in the Swedish Prosecution Authority's effort to extradite Mr Assange comes as another leading Swedish judge prepares to deliver an unprecedented public lecture in Australia next week on the WikiLeaks publisher's case. The Swedish Prosecution Authority wants to extradite Mr Assange to have him questioned in Stockholm in relation to sexual assault allegations by two women. Fairfax Media has obtained Swedish court documents that reveal high-profile Swedish prosecutor Marianne Nye has unexpectedly left Mr Assange's case from Wednesday, and has been replaced by a less-experienced prosecutor, Ingrid Isgren. The reasons for the change have not been disclosed yet. One of Mr Assange's two accusers, political activist Anna Ardin, also applied to the Swedish court on February 28 to replace her controversial lawyer, Claes Borgstrom. Ms Ardin said she found Mr Borgstrom spent much more time talking to the media than to her, referred her inquiries to his secretary or assistant, and that she had lost faith in him as her legal representative. Ms Ardin's engagement of a new lawyer, Elisabeth Massi Fritz, has now been approved. Swedish Supreme Court judge Stefan Lindskog will deliver a lecture on ''The Assange affair, and freedom of speech, from the Swedish perspective'' at the University of Adelaide on Wednesday. Mr Assange condemned Judge Lindskog's planned discussion of his case. ''If an Australian High Court judge came out and spoke on a case the court expected or was likely to judge, it would be regarded as absolutely outrageous,'' he said. Justice Lindskog is chairman of the Supreme Court of Sweden, the highest court of appeal. In announcing his forthcoming lecture, Adelaide University said that ''as one of Sweden's most eminent jurists, he is uniquely able to provide an authoritative view of the Assange affair''. Mr Assange now lives in the embassy of Ecuador in London where he has been granted political asylum on the grounds he is at risk of extradition to the US to face conspiracy or other charges arising from WikiLeaks obtaining thousands of secret US military and diplomatic reports.