Almost all of Nigeria's state governors are being investigated for corruption, the anti-graft agency head has said.
Nuhu Ribadu denied he was pursuing a political vendetta
Nuhu Ribadu told the Nigerian Senate that 31 of the 36 governors were being investigated and that 15 of them would be charged in the coming weeks.
He also said that the world's biggest thief was Nigerian but was prevented from naming him.
Critics of President Olusegun Obasanjo say the fight against corruption is being used as a political tool.
But Mr Ribadu denies these charges.
Nigeria's governors enjoy immunity from prosecution while in office and the country is regularly ranked as one of the world's most corrupt countries.
The president and vice-president have also swapped corruption accusations in recent weeks.
"If we all live in the US, all of us will be in prison by now, because the things we do here cannot be tolerated there," Mr Ribadu said.
The Economic and Financial Crimes Commission head said Zamfara governor Sani Ahmed Yerima was one of the worst cases of corruption.
"The case of Zamfara state is a tragedy - direct stealing - no third party," he said.
Mr Yerima, known for introducing strict Islamic punishments for thieves and adulterers, has said he is being persecuted for saying he wants to contest presidential elections next year.
Cross River State Governor Donald Duke was the only governor named by Mr Ribadu as not being under investigation for corruption.
Two state governors have been charged with money laundering in the UK but have been freed on bail and managed to return home.
However, former Bayelsa State Governor Diepreye Alamieyeseigha has been charged after the state legislature voted to remove his immunity.