Nigeria’s former national security adviser, Sambo Dasuki, has been arrested for allegedly stealing $2bn (£1.3bn), his representatives say.
Mr Dasuki is accused of awarding phantom contracts to buy 12 helicopters, four fighter jets and ammunition. He denies the allegations.
The equipment was meant for the fight against Boko Haram Islamist militants.
Mr Dasuki was picked up early in the morning by security agents, a PR firm representing him said.
Two weeks ago, President Muhammadu Buhari ordered Mr Dasuki’s arrest after he was indicted by a panel investigating the procurement of arm under the last administration of former President Goodluck Jonathan.
PRNigeria said he was picked up by intelligence agents from his home in the capital, Abuja, where he was already under house arrest facing separate charges.
Later on Tuesday, the former governor of Sokoto state, Attahiru Bafarawa and owner of a Lagos-based private TV station, Raymond Dokpesi, were detained separately by Nigeria’s Economic and Financial Crimes Commission (EFCC), in connection with the alleged fraud.
Both men, who are political allies of the former president, have denied any involvement in the arms deal.