Nigeria's leader on Tuesday ordered the arrest of the former president's national security adviser for allegedly stealing more than $2 billion (£1.3bn) meant to buy weapons for the military to fight Islamic militant Boko Haram rebels.
"Thousands of needless Nigerian deaths would have been avoided" if the money had been properly spent, Femi Adesina, an adviser to President Muhammadu Buhari, said in a statement.
It accuses Sambo Dasuki, a key adviser to former President Goodluck Jonathan, of awarding "phantom contracts" to buy 12 helicopters, four fighter jets, and bombs and ammunition worth $2 billion that never were supplied.
Mr Dasuki also got the Central Bank to transfer $142.6 million to a company with accounts in the United States, the United Kingdom and in West Africa for unknown purposes and without contracts, according to the statement.
Mr Dasuki denied any wrongdoing in an interview on Tuesday night with the PR Nigeria news agency, and said he was proud that in the final months under his watch Nigeria's military ousted Boko Haram from a self-declared Islamic caliphate set up after the rebels had taken control of a large swath of northeast Nigeria.
The offensive came as Mr Jonathan faced elections. Last year, soldiers told the AP they were going into battle without food and armed with only 30 bullets each.
Dasuki if guilty is worse than Shekau, he Undermined the Nigerian armed forces thus empowering Boko Haram. Allah ya isa.— N. (_at_NajeebWali) November 17, 2015
The State Security Service has kept Mr Dasuki under house arrest for more than a week despite a Federal High Court order allowing him to travel abroad for medical care. The court had allowed Mr Dasuki bail after he pleaded innocent to other charges of money-laundering, involving more than $423,000 found in cash, and illegal possession of arms seized at two of his homes.
The State Security Service, an agency formerly under Mr Dasuki's control, said he refused to answer questions about arms deals - charges he denied on Tuesday.
Social media buzzed with comments about revenge and pay-back. Mr Dasuki is said to have arrested Mr Buhari, a former military dictator who seized power from a democratically elected government, when he was deposed in a palace coup in 1985.
Tuesday's development follows an interim report by a presidential committee investigating arms procurement, part of the fight against Nigeria's endemic corruption that Mr Buhari has waged since taking office in May after defeating Mr Jonathan in elections.
Mr Dasuki, 60, a retired army lieutenant-colonel, participated in every coup in Nigeria going back to the 1980s
Mr Adesina says Mr Buhari has also ordered the arrest of several others linked to the scandal.