Former general secretary of Egypt's National Democratic Party (NDP) Safwat el-Sherif was detained on Monday for 15 days over corruption charges, state media said.
The decision came after a 12-hour interrogation with Sherif, the official MENA news agency said.
Sherif was a key ally of former President Hosni Mubarak who was forced to step down on Feb. 11 after 18 days of protests, he was also the speaker of the Shoura Council, or the upper house of Egyptian parliament.
He has been recently banned from traveling abroad with a number of other key figures in Mubarak's regime by prosecutors.
Sherif served as Egypt's minister of information for more than 20 years before he became the speaker of the Shoura Council. He resigned from the post of secretary-general of the NDP in early February after mass protests broke out to press Mubarak to step down.
A number of Mubarak-era officials have been detained and are facing trials over corruption accusation.
Egyptian Attorney General Abdel-Meguid Mahmoud decided Sunday to summon Mubarak and his two sons over accusations about the use of violence against protestors during the anti-government demonstrations.
In his first address since he stepped down on Feb. 11, Mubarak said he "will uphold all my legal rights to defend my reputation" and he and his family agreed to any measures to be taken to unveil their bank accounts overseas in a recorded audio speech aired by pan-Arab Al-Arabiya TV on Sunday.