A  Chinese journalist who called for President Xi Jinping’s resignation has disappeared. The Beijing-based journalist linked with an online petition calling for the Chinese president’s resignation disappeared without a trace from Beijing airport on his way to Hong Kong.

Hong Kong media reports have linked 41-year-old Jia Jia to an anonymous online petition asking the president to step down. His lawyer Yan Xin said that he cannot confirm whether the Chinese government is holding Jia, as authorities at the airport, local police, immigration services and the airline  could not give any information about him or his whereabouts.

Chinese police are required by the law to notify the family about a detained person within 24 hours unless it is related to state security.

Yan said, “The authorities will only answer our questions if we have a case to refer to but we haven’t received any notification of a case.”

Jia was booked to deliver a talk at the Hong Kong City University on Thursday, confirmed an employee of the university.  However, Jia failed to turn up, reported Radio Free Asia.

The employee said, “We don’t know what the situation is. All we know is that he didn’t show up.”

Jia’s wife told media that her husband made his last call around 8:00 pm on Tuesday from Beijing International Airport.  He was apparently already waiting to board a flight to Hong Kong. She also stated that it is unclear whether he was detained while he was still at the Beijing airport departure lounge or after he landed in Hong Kong.

One of his friends informed the media that Jia denied any link to the petition in a large online group chat, reported Economic Times. However, his friends believe that Jia’s disappearance was somewhat connected to the petition. The petition was posted in a government-linked site this month.

The New York-based Committee to Protect Journalists stated that Jia told his friends that police are looking for him in relation to the online petition published last March 4. The journalist also shared that police had gone to many of his relatives to confirm his involvement with the petition.