Egypt has arrested a University of Washington PhD student who was conducting research into the country’s judicial system.

Walid Al-Shobaky was brought before the Supreme State Security Prosecution on Sunday after being accused of spreading false news and joining a terrorist group. Al-Shobaky was last seen on Wednesday, after which he went missing for four days. On Sunday he appeared before the prosecution and was handed a 15-day detention order.

Mokhtar Mounir, a lawyer who works at the Association for Freedom of Thought and Expression, said that Al-Shobaky was brought before the prosecution without a lawyer.

Law and Philosophy Professor at Zagazig University, Nour Farhat, posted on his Facebook page that he had received a phone call from Al-Shobaky’s relatives informing him of Al-Shobaky’s disappearance, according to the New Arab. Farhat added that he had met Al-Shobaky in his office on the day he disappeared to discuss the cultural context of the establishment of Egypt’s judicial system. He explained that Al-Shobaky “told me that he had met with a number of prominent law and judiciary experts in Egypt, before coming to me for help with his research. Today his brother messaged me on Facebook, saying that he cannot be reached.”

Read: Egypt arrests prominent activist and blogger Wael Abbas

The case in which Al-Shobaky is implicated, known as Case 441/2018, also includes Wael Abbas, a prominent blogger and activist who was arrested last week. Abbas was taken during a 4am raid on his Cairo home and his computer and mobile phone were seized before he was transported to an unknown location. Abbas’ disappearance prompted friends and followers to launch the Arabic hashtag “where_is_Wael_Abbas” on Twitter. Abbas was arrested under almost identical charges to Al-Shobaky, with Egyptian security officials confirming he was detained on accusations of disseminating false news and joining an outlawed group.

Others implicated in Case 441/2018 include journalists Mostafa Al-Asar and Hassan Al-Banna who were disappeared in February, and lawyer and head of the Egyptian Coordination for Rights and Freedoms, Ezzat Ghoneim, who was disappeared in March.

Al-Shobaky’s arrest is reminiscent of the ordeal endured by Italian PhD student Giulio Regeni, who was tortured and murdered in 2016 while researching Egypt’s independent trade unions. Regeni was missing for nine days before his body was found near a highway between Cairo and Alexandria. Experts believed Regeni’s murder bore “all the hallmarks of an extrajudicial killing by the state’s security police”, according to the Guardian. Two years after his murder, in January 2018, an Italian prosecutor concluded Regeni had been killed because of his research into Egypt’s independent labour unions. Egyptian officials continue to deny any involvement in his murder.