CAIRO — The Egyptian state security prosecutor's office has again extended the detention of activist Ramy Shaath, the son of a former Palestinian foreign minister, on suspicion of having terrorist ties, an accusation his family denies.

Shaath was arrested July 5 at his Cairo home after prosecutors added him to a list of previously arrested suspects that includes journalists, businessmen, politicians and former members of the Egyptian parliament, and involves 19 companies. All the suspects are accused of being members of and funding the Muslim Brotherhood, which Egypt considers a terrorist group.

The Shaath family issued a statement Aug. 21 saying, "A large number of heavily armed security men stormed ... and searched his residence without providing any legal document to allow them to do so. ... [They] seized computers, CDs and cellphones.” When Shaath asked for an explanation, the security officers didn't reply, according to the statement, which was published on the Egyptian Commission for Rights and Freedoms website. The statement also said Shaath's wife, Celine Lebrun-Shaath, a French national, was deported without being able to contact the French Embassy in Cairo.

Ramy Shaath's family demanded that the security forces release him immediately “given the lack of evidence against him, and to allow his wife’s return as soon as possible to stand beside her husband, and because she works and lives in Egypt.”