The chief prosecutor of the international criminal court will face an external investigation into allegations of sexual misconduct, the court’s governing body has said. In a statement, the president of the body that oversees the ICC said the inquiry would examine the allegations against Karim Khan, which related to his alleged conduct towards a woman who worked for him. Since the allegations emerged last month, there has been intense behind-the-scenes negotiations among the court’s member states about the shape and scope of the investigation, as the court has scrambled to formulate a response to the allegations. Päivi Kaukoranta, the president of the governing body, the assembly of state parties (ASP), said an external investigation was being “pursued in order to ensure a fully independent, impartial and fair process”. She said the ASP was still finalising the “practical modalities of the investigation” and the “involved parties have been informed” that the court’s internal watchdog had been relieved from investigating the matter. She did not announce who would carry out the investigation. The external inquiry will examine the allegations against the prosecutor, which the Guardian reported last month include claims of unwanted sexual touching and “abuse” over an extended period, as well as coercive behaviour and abuse of authority. Lawyers for Khan, 54, have said he “denies the whole of the allegations”. On Monday he said: “I welcome the opportunity to engage in this process.” The alleged victim, a lawyer in her 30s who worked for Khan, has declined to comment. Multiple sources said ICC staffers were informed last week that the woman would be willing to assist an independent investigation. The announcement comes amid growing disquiet within the prosecutor’s office, which has about 450 staff, concerning Khan’s handling of the situation and attempts to suggest the allegations may be part of a smear campaign against him. Multiple ICC sources said some of Khan’s most senior staff had in recent weeks openly pushed for an external inquiry and advised him to take a leave of absence until it had concluded. Responding to the ASP’s announcement, Khan said he would remain in his role but his two deputy prosecutors would handle any issues relating to the allegations. “At my request, a coordination group chaired by the deputy prosecutors, acting independently and not reporting to me, has already taken responsibility for addressing all relevant issues connected to this issue internally within the office,” he said. He told the Guardian: “I will be continuing all other functions as prosecutor, in line with my mandate.” The external inquiry will replace efforts by the court’s internal watchdog, which Khan had asked to investigate the allegations – a move some of his staff have opposed due to concerns about its independence. Multiple senior ICC sources said the delay in establishing an external inquiry has exposed the court to attacks by those seeking to exploit the allegations to discredit the judicial body and undermine its investigation into the situation in Palestine. A panel of ICC judges is considering applications by Khan for arrest warrants for the Israeli prime minister, Benjamin Netanyahu, and his former defence minister for alleged war crimes and crimes against humanity in Gaza. Although many among Khan’s staff are alarmed by pro-Israeli interests seizing on the sexual misconduct allegations, there are concerns among senior ranks of his staff about his public response to the situation. Addressing the allegations last month, Khan said “this is a moment in which myself and the ICC are subject to a wide range of attacks and threats”. His lawyers later said the claims may have been released “to undermine his high-profile ongoing work at a delicate time”. Five ICC sources familiar with the situation said that while Israel or its allies might be attempting to take advantages of the allegations, many within Khan’s top team did not believe they had been invented by external actors hostile to the court. Pro-Israeli interests “may have exploited the story but they didn’t create the story”, one official said. When the claims were first reported internally in early May, Khan’s closest advisers are understood to have discussed whether the allegations could be part of an elaborate plot by Israeli intelligence agencies. At the time, the prosecutor was on high alert and sensitive to external threats but officials close to Khan concluded it was highly unlikely the allegations were part of an espionage operation. Sources within the prosecutor’s office said no evidence or intelligence had since emerged of any involvement of an intelligence agency, such as Israel’s the Mossad. Two sources said that if there had been genuine concerns that the alleged victim was part of a plot, she would have been removed from her position and her access to deliberations in the Palestine case would have been revoked, but this did not happen. “For a second I had my doubts, but if you look at the timeline and the details of how this came about it has nothing to do with any kind of plot,” one ICC official said. “I don’t think anyone in the [prosecutor’s] office seriously believes in that.”