7 April 2017.
The UK National Crime Agency (NCA) has been investigating Diezani Alison-Madueke, former Petroleum Minister, since 2013. She was arrested, on money laundering crges, in 2015 while she was undergoing treatment for breast cancer in the UK. She was later released on bail.

Sanusi Lamido Sanusi, who was at that time the acting governor of the Nigerian Central Bank, accused Diezani of pocketing $20 billion of oil revenue. Independent audit firms, including the KPMG and PriceWaterhousecoopers, have confirmed that billions of dollars of oil money were missing.
Recently, a Federal High Court issued an order allowing the country’s anti-graft body to confiscate over $150m belonging to her. Some of her choicest properties have been confiscated. Judge Muslim Hassan said that the Economic and Financial Crimes Commission (EFCC) had proven beyond reasonable doubt that the monies were proceeds from corrupt activity.
While she was transportation minister before becoming the oil and gas minister, Mrs. Alison-Madueke was investigated by the Nigerian Senate on allegation she paid N30.9 billion (US$ 101 million) to contractors. In 2009, the Senate indicted and recommended her prosecution for transferring N1.2 billion to a private account of a toll company.
Diezani was appointed as oil minister by the then President Goodluck Jonathan, who himself is said to have misappropriated country’s wealth during his tenure.
In the past, most of the Nigerians who have swindled money, escaped to the UK.  But now this has become difficult. James Ibori, a former governor of Nigeria’s oil-rich Delta State, was sentenced in 2012 to 13 years in prison by the UK Southwark Crown Court.  His houses, luxury cars and other property items were confiscated. Judge later ruled that his sentence be reduced to half. He was released in December last year after completing his 6 ½ years in prison. He returned to Nigeria this February.
Since May 2015, the Muhammadu Buhari administration has been prosecuting former officeholders in Jonathan’s administration. A former Finance Minister, Nenadi Usman, is said to have returned part of the money he stole to the government.