Nigeria's former oil minister and OPEC president Diezani Alison-Madueke was first arrested in London in October 2015
Nigeria's former oil minister and OPEC president Diezani Alison-Madueke was first arrested in London in October 2015 AFP

Former OPEC president Diezani Alison-Madueke has been charged with bribery offences relating to her time as Nigeria's oil minister, the UK National Crime Agency said on Tuesday.

Alison-Madueke, 63, has been on bail since first being arrested in London in October 2015. She will appear in court in the British capital on October 2, the NCA said.

Soon after her arrest, her family's lawyer told AFP she would strongly contest corruption allegations that have dogged her during and after her time in former president Goodluck Jonathan's government.

Alison-Madueke, in office from 2010 to 2015, was the first woman to be oil minister in Nigeria and the first female president of the global oil cartel OPEC.

The head of the NCA's international corruption unit, Andy Kelly, said in a statement: "We suspect Diezani Alison-Madueke abused her power in Nigeria and accepted financial rewards for awarding multi-million pound contracts."

The NCA said Alison-Madueke allegedly benefited from at least GBP100,000 ($127,000) in cash, chauffeur-driven cars, flights on private jets, luxury holidays for her family, and the use of multiple London properties.

The charges also detail financial rewards including furniture, renovation work and staff for the properties, payment of private school fees, and gifts from top designer shops such as Cartier jewellery and Louis Vuitton goods.

"Bribery is a pervasive form of corruption, which enables serious criminality and can have devastating consequences for developing countries," Kelly said.

"These charges are a milestone in what has been a thorough and complex international investigation," he added.

Alison-Madueke has been living in the upmarket St John's Wood area of north London since she was first arrested, and undergone chemotherapy for breast cancer, according to her family.

At the time of her arrest, the NCA said only it had detained five people in London on suspicion of international corruption, without naming those held.

The Nigerian government of Jonathan's successor Muhammadu Buhari later confirmed Alison-Madueke's arrest and said its law enforcement agencies were cooperating with their British counterparts.

Former army general Buhari began an anti-corruption drive after taking office.

The NCA said that assets worth millions of pounds in relation to the case have been frozen as part of the investigation.

In March, the agency, which targets international and organised crime, provided evidence to the US Department of Justice allowing them to recover assets totalling $53.1 million linked to Alison-Madueke's alleged corruption.