Cairo - Egypt's military prosecution has ordered a former anti-corruption chief detained for two weeks after he suggested a sidelined presidential candidate possessed damning material against leading officials, state media reported on Wednesday.
Hisham Geneina had been arrested on Tuesday following his remarks in an interview published by Huffpost Arabi.
Geneina had been a top campaign aide to former military chief-of-staff Sami Anan, whom the military also detained after he announced he would stand in next month's presidential election against incumbent Abdel Fattah al-Sisi.
Anan is accused of having declared his candidacy illegally while still a registered officer in the military, as well as incitement against the armed forces.
Geneina is accused of spreading "false news that harms national Egyptian security and affects the military institution and threatens authority," the official Al-Ahram newspaper reported.
His detention may be renewed after 15 days as the military prosecution investigates.
His lawyer Ali Taha told AFP he has not been informed of Geniena's whereabouts, but his client still needs treatment after an altercation last month.
Geneina had been taken to hospital with a fractured eye socket and other injuries. He blamed the attack on thugs in the pay of officials. Police said it was a traffic dispute.
"He had an operation in his eye. It can fall out. He has to sleep in a certain position. If you must detain him, detain him in a hospital," his lawyer said.
Geneina was sacked by Sisi as head of the Central Auditing Authority in 2016 after being accused of exaggerating the cost of corruption in Egypt.
Geneina said the documents Anan allegedly possessed "revolve around political events and crises Egyptian society has passed through" since the January 2011 uprising which toppled veteran strongman Hosni Mubarak.
The uprising left a military group led by Anan and commander-in-chief Hussein Tantawi in control of the country.
Anan had been the most credible election rival to Sisi, who is all but certain to win.
His only remaining rival is a leader of a small party who had been a leading campaigner for Sisi until he abruptly announced his own candidacy.
Critics said he did so to save Sisi the embarrassment of being the only candidate, in a throwback to referendums held by Egyptian autocrats instead of elections.
The government has rejected such criticism and the candidate, Moussa Mostafa Moussa, insists he is a serious contender.
Sisi, a former defence minister, came to power after ousting his Islamist predecessor Mohamed Morsi following mass protests against the Muslim Brotherhood member.
Sisi won an election a year later.
Former army general and prime minister Ahmed Shafiq had also announced he would stand in the election.
Shafiq made his announcement from exile in the United Arab Emirates, which promptly sent him back to Egypt where he was received by state officials who took him to a hotel.
Shafiq later withdrew his candidacy.