Egyptian Ceramica Cleopatra Club player Mido Jaber has disappeared from one of the army's chain of hotels under mysterious circumstances.
Under the Arabic hashtag, where is Mido Jaber, football fans have called on the security services to admit where he is amid accusations that he has been forcibly disappeared.
Moataz Al-Batawi, the club supervisor, said that Jaber had trouble getting into his room during a football camp at a hotel in the Fifth Settlement in Cairo.
He asked a member of staff to help, who later informed him that he needed to go to the reception himself to find out what was happening.
Two people in the reception asked if they could take a photo with him, went outside the hotel with him, and from around 8.30pm onwards his phone was switched off.
The hotel management have refused to hand over the CCTV footage.
Circulating online is a video clip of Zamalek Club President Mortada Mansour announcing that Jaber and his family are Muslim Brotherhood members.
Shortly after the coup in Egypt, the Muslim Brotherhood was outlawed and all members persecuted. Opposition figures, even if they were outspoken critics of the group, have also been arrested and tortured on the allegation they are members of the Muslim Brotherhood.
In 2015 Egyptian football star Mohamed Abu Trika had his assets frozen after being accused of involvement with the Brotherhood.
In 2017 he was added to a terror list over his alleged ties to the group.
That same year, Aswan player Hamada Al-Sayed was forcibly disappeared and detained for two years before finally being acquitted of charges against him.
Al-Sayad was accused of joining the Sinai Province terror group.