UK’s leading anti- organized crime agency NCA has charged Nigeria’s former oil minister Diezani Alison-Madueke on suspicion of accepting financial rewards for awarding multi-million-dollar oil and gas contracts.

The 63-year-old, who has been on bail since her arrest in London in 2015, has denied corruption allegations.

Assets worth millions of pounds relating to the alleged offences have been frozen as part of an ongoing probe by the NCA.

“These charges are a milestone in what has been a thorough and complex international investigation,” Andy Kelly, from the NCA’s International Corruption Unit, said.

The NCA said Ms Alison-Madueke is alleged to have benefited from:

• At least £100,000 ($127,000) in cash
• Chauffeur-driven cars
• Flights on private jets
• Luxury family holidays
• Use of multiple London properties
• Furniture, renovation work and staff for the properties
• Payment of private school fees
• Gifts from designer shops such as Cartier jewellery and Louis Vuitton goods.

The US Department of Justice has been able to recover assets totalling $53.1m linked to Ms Alison-Madueke’s alleged corruption thanks to evidence provided by the NCA in March, the agency says.

The NCA added that its agents had also worked closely with Nigeria’s anti-corruption agency, the Economic and Financial Crimes Commission (EFCC).

Last year, the EFCC said about $153m and more than 80 properties had been recovered from the politician, who served as oil minister from 2010 until 2015.

Ms Alison-Madueke, who currently lives in London’s St John’s Wood suburb, will appear at Westminster Magistrates Court on 2 October.