The Metropolitan Police is facing its most damaging race row since the fall out from the murder of Stephen Lawrence as black police associations line up behind the UK’s most senior Muslim officer.
Colleagues who have seen Assistant Commissioner Tarique Ghaffur’s case for racial discrimination against the force described it as “astonishing”.
They said evidence of bullying, discrimination and victimisation against Mr Ghaffur was compelling.
The National Black Police Association said the officer, who has been responsible for Olympic security preparations, had been treated “extremely poorly”.
It called on Home Secretary Jacqui Smith to intervene in a row that threatens to plunge the force into its biggest crisis since the murder of Stephen Lawrence, which led to the Met being branded “institutionally racist” in the 1999 Macpherson inquiry.
Mr Ghaffur is currently deciding whether to formally submit his dossier of evidence to an employment tribunal.
But senior members of the NBPA, who have have seen the documents, said they were “totally and utterly convinced” that he has a legitimate claim.
Among the documents are believed to be allegations of victimisation by Commissioner Sir Ian Blair and Metropolitan Police Authority chair Len Duvall.
Both Sir Ian and Mr Duvall have publicly denied that they behaved inappropriately in any way.
An NBPA spokesman said: “Having reviewed the evidence we are astonished at the amount of material which was presented to us in support of his case.
“Assistant Commissioner Ghaffur appears to have been treated extremely poorly.
“We are totally and utterly convinced of the legitimacy of this claim and will be fully supporting Mr Ghaffur.
“We are calling for an immediate intervention at a senior governmental level to prevent this dispute escalating.”
London Metropolitan Police Commander Ali Dizaei said he was “shocked” when he learned details of the allegations made by Mr Ghaffur.
Mr Dizaei said: “He is a very loyal, a very loyal person and extremely competent. For a person of his personality and character, to embark on this course of action, I think he is at the end of his tether. Some of the evidence was unequivocal.”
Relations between Mr Ghaffur and Sir Ian were said to have broken down to such an extent that they would only speak at formal meetings.
However, Sir Ian said that was “nonsense” and praised Mr Ghaffur as a role model.
Sir Ian said he would deal “robustly and quickly” with anyone in the Met who did not work to his direction.
He does not have the power to sack Mr Ghaffur but could refer the matter to the Police Authority for further investigation.
Asked if it was unfair for Sir Ian to be accused of racism, London Mayor Boris Johnson said : “I am sure that is unfair yes, but I do not want to get into the details of the case.”