CAIRO (Reuters) - An Egyptian military court has rejected an appeal by a former anti-corruption chief and opposition figure against his five-year prison sentence for spreading false news harmful to the military, his lawyer said on Sunday.

Shortly before his arrest, Hisham Genena had served on the campaign team of former military chief of staff Sami Anan, who was planning to run as an independent candidate against President Abdel Fattah al-Sisi in elections in March 2018.

But Anan’s presidential bid was cut short in when the military arrested him in January 2018 for allegedly running without permission.

Genena was arrested a month later after he told HuffPost Arabi news website that Anan possessed documents that were damning of senior officials, and in April a military court sentenced him to five years in jail for spreading false information.

His lawyer Hussam Lotfy told Reuters the sentence had been upheld. The verdict was subject to further appeal.

Genena’s daughter Shorouk told Reuters she believed the sentence was upheld “for political reasons, specially during the time while the constitution is being amended. They don’t want anyone to open their mouth or be outside (prison) during the coming period.”

Genena was fired as head of Egypt’s corruption watchdog in 2016 after the government accused him of exaggerating the scale of public sector graft.

“While unsurprising, the decision to deny Genena’s appeal is a disappointing continuation of Sisi’s efforts to repress anyone who dares to challenge him,” said Timothy Kaldas, non-resident fellow at the Tahrir Institute for Middle East Policy.

Parliament is currently debating proposed constitutional changes that could allow Sisi to stay in power until 2034 and tighten his control over the judiciary.

“The broader roundup of critics should be understood in the context of a campaign of intimidation designed to minimize resistance to Sisi’s efforts to amend the constitution and rule Egypt for decades,” Kaldas added.

In one such incident, four members of the liberal Al Dostour Party were arrested on Feb. 22. The party’s lawyer said he believed the arrests were connected to their opposition to the constitutional amendments.

“They announced that they reject the constitutional amendments. That’s the extent of their activity, which is the position of the party and a legitimate political activity,” he said.

The four - Gamal Fadel, Helal al-Masri, Ahmed Rasam and Ramadan Abu Zeid - have not been formally charged, but the investigations revolve around incitement and joining a banned group, the lawyer said on condition of anonymity.

Separately, a man was detained in Tahrir Square after holding a sign calling on Sisi to quit. The man posted a video on social media saying he was being taken away in a police car, and his lawyer said his whereabouts remain unknown.