Britain's most senior Asian policeman has compiled an "astonishing" dossier of evidence which supports his racism claims against Scotland Yard, a lobby group for black officers said.
Assistant Commissioner Tarique Ghaffur has been "treated extremely poorly," the National Black Police Association (NBPA) added and called for Home Secretary Jacqui Smith to intervene.
The increasingly bitter race row has pitted Ghaffur against Metropolitan Police Commissioner Ian Blair.
The row, made public this week, forced Blair to issue a rare public statement in a bid to quell mounting concern about racism in London's police force.
It also forced the pair into crisis talks on Thursday.
A Met spokesman declined to reveal their outcome.
Media reports have said Ghaffur, the officer in charge of security for the London 2012 Olympics, is preparing to sue his boss for racial discrimination.
Ghaffur, who has employed a senior lawyer to fight his case, alleges he has been humiliated and undermined by the Metropolitan Police.
The Met's third most senior officer has passed his dossier of allegations to the NBPA, which media reports said contained specific allegations of victimisation by Blair and Police Authority chairman Len Duvall.
"Having reviewed the evidence (from Ghaffur) we are astonished at the amount of material which was presented to us in support of his case," an NBPA statement said on Friday.
"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 with regard to this matter."
Blair's public statement on Thursday hinted Ghaffur might be sacked if disagreement persists.
It said: "I hope that this will be resolved satisfactorily between us but will state here publicly that every member of the Met works to my direction and must meet my reasonable requirements.
"Any other position is impossible," it added. "If that doesn't occur, then I will deal with the matter robustly and quickly."
A Home Office spokesman had no immediate comment.
