Nigerian police said on Thursday they had recovered the ceremonial mace - the parliamentary symbol of authority - under a flyover after it was stolen from the Senate.The mace was snatched on Wednesday by "hoodlums" suspected to have been hired by an embattled senator who had been suspended from the upper house because of a dispute over the date of the presidential election next year.Seizing the mace has been a long-established tactic to express discontent with parliamentary proceedings in the Senate and the lower House of Representatives, as well as state legislatures. The Senate described the theft in the capital Abuja as an "act of treason" and gave police 24 hours to retrieve the mace. Parliament cannot convene without the mace, a one-metre long metal rod traditionally carried by the Senate speaker upon entering and leaving the chamber. Deputy police spokesperson Aremu Adeniran said a massive search operation was launched, forcing the suspects to abandon the mace under an Abuja flyover, "where a patriotic passer-by saw it and alerted the police". He said an investigation into the theft was ongoing. Ovie Omo-Agege, a senator from the oil-rich southern Delta state who allegedly led the intruders into the upper chamber was arrested for questioning on Wednesday but was later released after denying his involvement.In 2000, then-Senate speaker Cuba Okadigbo allegedly removed the mace from the chamber and took it to his hometown in a dispute with his deputy over when to resume parliament after recess.