Nigerian investigators on Wednesday arrested one of the country’s most powerful politicians. James Ibori, who is also being investigated by UK police for suspected money laundering, is accused of stealing state funds during his eight-year tenure as governor of the oil-producing Delta State, one of Nigeria’s richest.

Campaigners had complained that the government of President Umaru Yar’Adua, who has launched a campaign to crack down on corruption, has been slow to arrest Mr Ibori and other former governors accused of looting state funds since taking power after elections in April.