A former Nigerian oil minister accused of being treated to luxury home stays and lavish spending sprees in the UK in exchange for granting government contracts has denied asking for or taking bribes. Diezani Alison-Madueke, 65, told Southwark Crown Court on Monday that she had 'tried to push back on corruption' in a country plagued by it since the days it was a British colony. Several Nigerian businessmen are alleged to have bankrolled huge spending sprees, including more than £2m at luxury store Harrods and £4.6m on refurbishing homes in London and Buckinghamshire. But the ex-minister said that the cost of services laid on for her while on official duties was later repaid. '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,' Alison-Madueke told the court. 'I always sought to act impartially.' She added that money spent on her behalf was reimbursed by the state-owned Nigerian National Petroleum Company (NNPC), and explained that a service company was set up in London because the financial structure of the NNPC was in a mess. The prosecution's case is based on allegations that Alison-Madueke was given access to a 'grand' home in Buckinghamshire and other multimillion-pound properties while allegedly benefiting from renovations valued at £4.6m. Throughout her testimony, Alison-Madueke defended her actions and explained the reasons behind her accommodations, asserting these were all official and above board. As the trial continues, she has denied five counts of accepting bribes and a charge of conspiracy to commit bribery.