With his outspoken campaigning on race relations and solid reputation for day-to-day crime-fighting, Superintendent Ali Dizaei had been tipped to be Britain's first Asian chief constable.
Mr Dizaei was cleared of perverting the course of justice in April
He began his career in the well-to-do town of Henley-on-Thames, where he still lives, earning a name for tackling teenage drink and drug abuse.
The Iranian-born officer later became an adviser on race to the Home Secretary and moved into a £52,000 a year job in the London borough of Kensington and Chelsea.
But Supt Dizaei was himself secretly suspected of crimes and in 2000 became the subject of what was to become the most expensive inquiry ever into a single officer.
Three years later he has been cleared of perverting the course of justice, misconduct in public office and making false expense claims - leading to renewed claims that the Metropolitan Police has failed to stamp out racism.
With his flamboyant taste for designer clothes, self-confessed open marriage and taste for expensive nightclubs, Supt Dizaei was never a straightforward member of the police rank and file.
It was said that the father of three was intensely disliked by some colleagues who described his sunglasses and cowboy
boots as "flash".
Supt Dizaei was described as a keen bodybuilder who rarely socialised with other officers.
But the gossip about his lifestyle was accompanied by more serious concerns and Supt Dizaei was investigated for allegedly using drugs and prostitutes and taking bribes - all these claims were later dropped.
It was even claimed that he worked for the Iranian secret service- allegations which Mr Dizaei has not been able to confront because much of the evidence against him was not revealed in open court.
Defending Supt Dizaei, Michael Mansfield QC said: "The suggestion actually is that he remains a threat to national security.
"If he is a threat to national security, why has he not been charged? The answer appears to be: 'We cannot tell you'."
Speaking after the last of the charges were dropped, Supt Dizaei said he believed there had been a campaign by individuals to "destroy my life and my career".
With some estimates putting the official £3m cost of the investigation closer to £7m he said that he found it "astonishing and extraordinary" that so much taxpayers' money had been used against him.
Mr Mansfield accused police of a "witch-hunt" which led to nothing more than a trial over a scratched car.
Peter Herbert, chair of the Society of Black Lawyers, said the case showed the Metropolitan Police had failed to learn from the mistakes of the Stephen Lawrence case.
He said it appeared to be a "clear case of institutional racism, victimisation and quite possibly an abuse of process designed to extinguish this officer's career
In a statement the Metropolitan Police said it had acted because: "Honesty and integrity are key values for any police officer and the police service must take steps to investigate those whose behaviour is called into question."
It said it had carefully handled what was a sensitive case and that Supt Dizaei's allegations of unfairness and prejudice had been rejected by the Recorder of London.
Scotland Yard added: "The Metropolitan Police are now in a position to consider any outstanding internal police disciplinary issues previously mentioned in court.
"It would be inappropriate for us to comment further on these matters at this stage as to do so may potentially prejudice possible future proceedings."