Diezani Alison-Madueke, a former Nigerian petroleum minister, took the stand at Southwark Crown Court in London on Monday to firmly deny that she ever sought or accepted bribes during her tenure in office. "I can state categorically that at no point did I ask for, take or receive a bribe of any sort from these persons and did not abuse my office," the 65-year-old told the court, adding that she had "tried to push back on corruption" in a country she described as having been plagued by it since the days of British colonial rule.

Alison-Madueke served as Nigeria's minister of petroleum resources between 2010 and 2015, overseeing Africa's largest oil producer and becoming the first female president of OPEC — the Organisation of the Petroleum Exporting Countries, the influential cartel that coordinates oil output among major exporting nations. She faces five counts of accepting bribes and one charge of conspiracy to commit bribery. Prosecutors allege that several Nigerian businessmen bankrolled an extravagant lifestyle on her behalf in exchange for government contracts, including more than £2 million in spending at luxury department store Harrods, £4.6 million spent refurbishing properties in London and the English county of Buckinghamshire, access to a £2.8 million home in Marylebone, residences overlooking Regent's Park, and approximately £100,000 in cash allegedly delivered by one of her drivers.

In her defence, Alison-Madueke insisted that all expenses incurred during her official duties abroad were subsequently reimbursed by the Nigerian National Petroleum Company (NNPC), the state oil firm. She explained that a logistics company had been established in London to manage travel and accommodation arrangements because the NNPC's internal financial structure was, in her words, "in a mess." She described some of the properties cited by prosecutors as venues for discreet official meetings, while others she said were either arranged without her knowledge or were uninhabitable at the time. On the £100,000 cash delivery, she told the court she had been unaware of it and that it had nothing to do with her. She also noted that she had raised security concerns, saying that as a female minister in what she called "a very patriarchal society," she faced serious kidnapping threats.

Also standing trial are oil industry executive Olatimbo Ayinde, who denies one count of bribery and one count of bribing a foreign public official, and Alison-Madueke's brother, former archbishop Doye Agama, who denies conspiracy to commit bribery. Nigerian businessman Kolawole Aluko, whose payment cards are alleged to have been used to fund some of the disputed expenses, is not among the defendants.

The case carries significant weight beyond the courtroom. Alison-Madueke, who relocated to the United Kingdom after Nigeria's ruling Peoples Democratic Party lost the 2015 presidential election, also faces multiple corruption proceedings in Nigeria, several of which have stalled due to her prolonged absence. Nigerian courts have already ordered the forfeiture of assets worth billions of naira linked to her, with some properties and valuables located in both the United States and the United Kingdom. The trial is expected to shed further light on the murky relationship between public officials and private energy firms that has long defined Nigeria's oil sector — one of the world's largest but also one long beset by governance failures.