CAIRO, Feb. 13 (Xinhua) -- Egypt's military prosecution decided Tuesday to detain Hisham Geneina, the former anti-corruption chief, for 15 days pending investigation into his claim about the presence of classified documents overseas.

Geneina, former director of of Egypt's Central Auditing Authority, said in a recent interview with the HuffPost Arabi news website that former military chief of staff Sami Anan, currently in custody, keeps abroad secret documents and evidence that could convict senior Egyptian officials of crimes in major events since the ouster of former President Hosni Mubarak in early 2011, the state-run news agency MENA reported.

In response, the military spokesman said that the army will refer the issue to the concerned authority for probe, accusing Geneina of "attempting to raise doubts about the state and its institutions."

The police arrested Geneina earlier on Tuesday and he was later taken to the military prosecution for interrogation.

The former top auditor is a supporter of Anan, who was arrested last month pending military investigation over announcing a run for the 2018 presidential election without prior permission from the armed forces as required.

The army also accused Anan of falsifying official documents stating he had ended his service in the armed forces.

Geneina said in the interview that he was beaten by a number of thugs outside his house in Cairo in late January, which prevented him from holding a scheduled meeting with a lawyer to appeal Anan's detention.

Egypt's presidential election is scheduled for late March. Incumbent President Abdel-Fattah al-Sisi is expected to make an easy win for a second term due to the lack of strong challengers in the race.