The suspended governor of a Nigerian province has been quizzed by Scotland Yard over money laundering allegations involving more than £1m ($1.7m).
Fraud Squad began investigations at the start of the year
The Nigerian High Commission confirmed Plateau State governor Joshua Dariye was questioned by police and freed on unconditional bail.
The allegations are linked to a scheme involving oil revenue and other public funds, the British Embassy said.
Mr Dariye was suspended in May for not controlling violence in the state.
Nigerian President Olusegun Obasanjo took the action following religious violence which left hundreds dead.
At the time he declared a state of emergency and accused the governor of neglecting his duties by failing to maintain order as a "mutual genocide" between Christians and Muslims broke out.
Plateau is an agricultural state the country's central highlands some 200 miles east of the capital Abuja.
Fraud Squad detectives began investigating Mr Dariye in January this year, four months before he was suspended, and are looking at his UK bank accounts.
Three others - two women and a man - have been arrested by the fraud squad in connection with the money laundering case.
They have also been bailed pending further inquiries.
Oil-rich Nigeria is regarded by the Berlin-based anti-corruption watchdog Transparency International as the second most corrupt country in the world.