An Egyptian rights lawyer says a former diplomat who called for a referendum on Egyptian President Abdel-Fattah el-Sissi's government has been released from jail.

Khaled Ali says his client, Masoum Marzouk, was released earlier this week along with four activists.

Marzouk was arrested in August 2018, shortly after calling for a referendum and a "popular conference" in Tahrir Square — epicenter of the 2011 uprising — if the government rejected his proposal.

El-Sissi's government has rolled back many of the freedoms won in 2011, banning unauthorized protests and jailing thousands of people since 2013. He was re-elected in March 2018 after all serious challengers were either arrested or pressured into leaving the race.

Marzouk was released Thursday, pending an investigation into terror-related charges.