Nigeria’s former oil minister was arrested in London on Friday, according to reports.
Diezani Alison Madueke held the role for five years under the presidency of former leader Goodluck Jonathan.
The UK National Crime Agency (NCA) said five people had been arrested across London as part of an investigation into suspected bribery and money laundering offences.
It is understood Madueke was granted bail a few hours after being arrested.
The news comes as Nigeria’s President Muhammadu Buhari said he would retain the government’s oil portfolio following the establishment of his new cabinet.
A spokesman for the NCA said: “On Friday 2nd October, the National Crime Agency’s recently formed International Corruption Unit arrested five people across London as part of an investigation
into suspected bribery and money laundering offences.
“All five people arrested were released on conditional police bail later that evening, pending further investigation both in the UK and overseas.
“The investigation commenced in 2013 under the Proceeds of Corruption Unit, and transferred to the NCA earlier this year.”
When Buhari took office in May this year he promised to root out corruption in Africa’s oil rich country.
In a sign that the arrest had been coordinated with Nigerian authorities, the financial crimes unit sealed one of Alison-Madueke’s houses in the upmarket Asokoro district in the capital Abuja, two security officials said.
During her time in office, former central bank governor Lamido Sanusi was sacked after he raised concern that tens of billions of dollars in oil revenues had not been remitted to state coffers by the government-run oil company NNPC between January 2012 and July 2013.
Buhari said on Sunday that the prosecution of those suspected of misappropriating the NNPC’s revenue under past administrations would begin soon.