CAIRO (Reuters) - An Egyptian lawyer who is helping investigate the case of murdered Italian student Giulio Regeni was prevented from flying to a U.N. conference and detained by a special prosecutor, his supporters and a security source said. Ibrahim Metwaly, who founded the Association of the Families of the Disappeared after his son disappeared in suspicious circumstances four years ago, himself went missing while heading for his flight to Geneva on Sunday. Members of his group said he was taken from Cairo airport by airport security and he was not heard from until Wednesday when a state security prosecutor ordered him detained for 15 days on charges of  joining a group founded illegally , judicial sources said. There was no comment from the Interior Ministry. A security source said Metwaly was legally arrested and not subjected to any violations.  Rights activists say Egyptian security forces resort to kidnapping government opponents and keeping them in secret jails where they can spend weeks, months, or years without charge. The authorities deny the accusation. Italian graduate student Giulio Regeni, who was conducting research on Egyptian trade unions, disappeared in Cairo on Jan. 25 last year. His body was discovered in a ditch on the outskirts of the Egyptian capital on Feb. 3, showing signs of extensive torture. Metwaly has been assisting lawyers working on the Regeni case as an expert on enforced disappearances, according to one of the lawyers.  I have no doubts Ibrahim s arrest was in connection to the Regeni case and his upcoming trip,  a source at the Egyptian Commission for Rights and Freedoms (ECRF), a Cairo-based NGO, told Reuters. ECRF lawyers are providing legal representation for the Regeni family in Egypt. Metwaly s son Abdelmoniem Metwaly said his father was now in a Cairo jail and that he was also charged with  conducting espionage on behalf of a foreign entity , something he said referred to the U.N. Working Group on Enforced or Involuntary Disappearances which he was due to address in Geneva. There was no immediate comment from the U.N. body. Regeni s murder has strained ties between Italy and Egypt, traditional Mediterranean allies with strong economic ties. Security and intelligence sources said Regeni was arrested the day he vanished and taken into custody. Egyptian officials have denied any involvement in his death. Italy recalled its ambassador in April 2016 as it sought to obtain evidence from Egypt to solve the murder. Magistrates in Rome and Cairo have met half a dozen times over the past year but no one has been charged.  A new Italian ambassador arrived in Cairo on Wednesday. Pier Antonio Panzeri, an Italian lawmaker who chairs the European Parliament s Subcommittee on Human Rights, said in a statement:  I am disturbed by alleged reports that lawyer Ibrahim Metwaly was arrested ... while he was about to fly to Geneva to address the U.N. Working Group.  
Lawyer assisting in murdered Italian student investigation detained in Egypt