Two former aviation ministers have been arrested by Nigerian anti-corruption agents investigating the disappearance of $160m to buy radar equipment. Femi Fani-Kayode and Babalola Borishade were detained after giving evidence to a Senate inquiry into the case. Both men denied any wrong-doing and Mr Borishade said that the amounts of money concerned had been exaggerated.

The equipment was supposed to help improve Nigeria's woeful air safety record after several fatal crashes.

Mr Borishade was sacked as aviation minister after a 2006 crash at the airport in the capital, Abuja, which killed 97 people, including the spiritual leader of Nigeria's Muslims.

Mr Fani-Kayode, a spokesman for former President Olusegun Obasanjo who left office last year, then replaced him. Correspondents say it is expected that the two will be charged in court in the coming days, where they are expected to enter a formal plea.

Also detained on Monday was Roland Iyayi, former head of the federal aviation agency.

Last week, an Austrian aviation contractor was arrested after giving evidence.

More than 200 people were killed in two crashes in 2005.