A fraudster who “tricked his way” into becoming a  governor of one Nigeria’s oil producing states has pleaded guilty to 10 counts of money-laundering and conspiracy to defraud at a London Court.

James Ibori, a former governor of one of Nigeria’s oil-producing states, was accused by British police of stealing $250m (£160m) over eight years. He changed his plea to guilty as  his trial at London’s Southwark Crown Court was about to begin and admitted stealing money from Delta state and laundering it in London through a number of offshore companies.

Ibori was arrested in 2010 in Dubai and then extradited to London.

Some $35m of his alleged UK assets were frozen in 2007.

Prosecuting QC Sasha Wass said Mr Ibori, 53, had “tricked” his way into becoming Delta state governor, by giving a false date of birth and claiming he had no criminal record.

“He was never the legitimate governor and there was effectively a thief in government house. As the pretender of that public office, he was able to plunder Delta state’s wealth and hand out patronage.”

He is due to be sentenced on 16 April.

Mr Ibori’s wife, Theresa, his sister, Christine, his mistress, Udoamaaka Okoronkwo, and his London solicitor, Bhadresh Gohil, have all been convicted of money-laundering.

Their convictions could only be reported on Monday after reporting restrictions were lifted.

Nigeria’s Economic and Financial Crimes Commission (EFCC) had asked the UK’s Metropolitan police to look into the ex-governor’s financial affairs.

“The vast sums of money involved were used to fund Mr Ibori’s lavish lifestyle,” Detective Inspector Paul Whatmore, the officer in charge of the investigation, said.

“We will now be actively seeking the confiscation of all of his stolen assets so they can be repatriated for the benefit of the people of Delta State.”