Lisa Osofsky, the director of the Serious Fraud Office (SFO), was found to have made “numerous errors and misjudgments” in her handling of a prosecution that eventually resulted in the convictions of two businessmen being overturned. Osofsky accepted she had made mistakes following what she admitted was a “gentrifying” review of the SFO’s performance. The review by Sir David Calvert-Smith, a former director of public prosecutions and high court judge, found a series of “fundamental failures” by senior SFO officials. The attorney-general, Suella Braverman, tasked Calvert-Smith with looking into how and why appeal court judges overturned the businessmen’s bribery convictions after concluding the SFO had failed to hand over vital evidence. The businessmen – Ziad Akle and Paul Bond – had been jailed for their roles in a corrupt scheme run by a consultancy firm, Unaoil, which paid huge bribes to win commercial contracts around the world for years. Judges said the SFO had withheld “embarrassing” evidence which would have detailed its “grossly inappropriate” dealings with a private investigator, David Tinsley, who was described as a fixer. Other businessmen involved in the case had hired Tinsley to try to secure more favorable sentences for them. In his report published on Thursday, Calvert-Smith described how Osofsky “had to make some sensitive and serious decisions” about the Unaoil prosecution soon after she was appointed director of the SFO in 2018. She said a former colleague had recommended she meet with Tinsley and, soon after, she faced a decision to sack Tom Martin, the SFO lawyer who led the investigation. A tribunal later ruled that Martin had been unfairly dismissed by the SFO. Ziad Akl. Photo: Daniel Leal-Olivas/AFP/Getty Images “It is clear that Osovsky faced a difficult situation very early in her tenure and made a series of mistakes and misjudgments that, with the benefit of hindsight, she now accepts.” Calvert-Smith said Osovsky “should not have personally engaged” with Tinsley, who had no recognized legal role in the case. Some of them were not recorded. Calvert-Smith said Osofsky’s interactions with Tinsley, which included flattering text messages from him, encouraged SFO prosecutors to believe she and senior staff had given the investigator a “seal of approval”. Consequently, prosecutors believed they could not rule Tinsley out despite their misgivings and felt compelled to meet with him on several occasions. The businessmen were acquitted after their lawyers argued that Tinsley’s frequent but unknown contact with the SFO had undermined their chances of a fair trial. Calvert-Smith said Osofsky was at fault for failing to consult widely with her colleagues about the wisdom of her interactions with Tinsley, adding that she could have avoided later criticism from judges that led to the convictions being overturned. Osofsky said implementing a series of recommendations to improve the SFO was “our pressing priority.” He added: “The SFO of today is no longer the same organization that I inherited.” Sue Hawley, director of campaign group Spotlight on Corruption, said: “This is a grim day for the SFO.”