A former Nigerian oil minister has appeared in court in London after being charged with receiving bribes in exchange for multi-million- dollar oil and gas contracts.

Diezani Alison-Madueke was Nigeria's minister for petroleum resources between 2010 and 2015, during the tenure of former President Goodluck Jonathan.

She was also the first female president of the oil bloc, Opec.

Britain's National Crime Agency said she had received various forms of rewards - including cash, luxury goods and holidays.

The NCA said it had frozen assets worth millions of dollars related to the charges.

Mrs Alison-Madueke has denied the allegations and has been on bail since her arrest eight years ago.

She's facing similar charges in Nigeria and the United States.