Ali Dizaei believes he did not fit in with his colleagues

On Monday allegations that Superintendent Ali Dizaei fiddled �270 of travelling expenses were dropped in court.

On the same day it emerged that Mr Dizaei, from Henley-on-Thames, Oxfordshire, had already been cleared in another trial, back in April, of "perverting the course of justice and misconduct" over an accusation that he lied about damage to his BMW car.

Mr Dizaei, an outspoken critic of racism in the force, told BBC 2's Newsnight programme some fellow officers had simply wanted him out.

Describing their attitudes, he said: "We don't like him, he doesn't subscribe to our norms and values, he's not one of us, we can't have him in the club... he's a dissident."

The Iranian-born officer plans to go ahead with a racial discrimination employment tribunal case against the force.

There have also been several calls for an inquiry after the force staged a two-year, multi-million pound investigation into Mr Dizaei's conduct.

I think they tried to set Ali Dizaei up Peter Bottomley MP Dizaei had been 'set for top'

The probe took up thousands of hours of police time and included taping 3,500 of the officer's phone calls, and trying to set up a sting operation involving the FBI.

Mr Dizaei was second-in-command at Kensington police station in west London, and tipped to become the UK's first ethnic minority chief constable, before he was suspended from his �52,000-a-year job in 2001.

The trial at the Old Bailey heard that he had a glamorous and affluent lifestyle - including an open marriage - which made him unpopular with other officers.

'Possible spy'

He was seen by some to be ambitious, too critical of the police on race issues and too close to the wealthy Iranian community in his area.

Some of the allegations were so bizarre, I thought they were funny Ali Dizaei

Undercover officers spent two years investigating 30 allegations against the 41-year-old - including that he was corrupt, used prostitutes, was a possible Iranian spy and a drug user.

In the end, only two charges - of fiddling expenses, and of lying over damage to a BMW - were brought.

Peter Bottomley MP called for an independent investigation, saying: "I think they tried to set Ali Dizaei up... this case has not been in the public interest, every part of the police action since I've been involved has been unjustifiable."

[I have] serious concerns about the apparent bias, victimisation and institutional racism that appears to be behind the prosecution Peter Herbert, Society of Black Lawyers

Peter Herbert, a judge and chairman of the Society of Black Lawyers, also called for an independent inquiry into the "apparent bias, victimisation and institutional racism" driving the investigation.

"The implications of this are that once again the Met has demonstrated its inability to deal fairly with a black officer," he said.

But the Metropolitan Police defended their inquiry, denying that the case had undone all the good work on race relations within the force since the Stephen Lawrence inquiry.

Deputy Assistant Commissioner Stephen House said: "This was not about scratches on a car and fiddling expenses, but about the integrity and trust of an extremely senior police officer."

Mr Dizaei said he did not blame the force or the CPS but "a number of individuals in those two organisations who have set out on a personal crusade to try to destroy my life and my career".

Mr House said a decision would be made within the next few days about whether Mr Dizaei's suspension would be revoked - but pointed out that he still faces a hearing on 12 internal disciplinary matters.