Britain’s most senior Asian officer is preparing legal proceedings against the Metropolitan Police Commissioner, alleging racial discrimination at Scotland Yard.

Assistant Commissioner Tarique Ghaffur has had legal documents drawn up by a QC that allege a catalogue of victimisation, bullying and harassment. Some of the allegations are said to refer directly to the actions of the commissioner, Sir Ian Blair, and Len Duvall, who chairs the Metropolitan Police Authority. The claims threaten to engulf the Metropolitan Police in its biggest race dispute since the Stephen Lawrence murder, after which the force was accused of being institutionally racist.

The latest controversy is symptomatic of the infighting at Scotland Yard. There is barely concealed dissent and discontent among senior officers, with leading figures in policing jockeying to replace Sir Ian. His contract expires in February 2010 but with one of his most senior officers now in open revolt there will be doubts about whether he can remain in the post until then.

The move comes in the same week that Commander Shabir Hussain, another senior Asian officer, took the force to a tribunal and accused the commissioner of excluding black and Asian detectives in favour of a “golden circle” of white officers.

Mr Ghaffur will consult senior members of the National Black Police Association in London today but it is expected that he will go ahead with his legal action. A source close to him said that he was so angry about the way he had been treated that he had decided to “press the nuclear button”.

Another told The Times: “He is not being taken seriously, not spoken to and is being humiliated. He is not being involved in meetings and is being passed over when it comes to making decisions. The key point is that this is not about corporate Met, it is about individuals.”

The source said that he expected legal papers to be served within weeks.

The allegations by Mr Ghaffur, who is responsible for security at the 2012 Olympic Games, include being silenced over concerns about 42-day detention and being sidelined by the commissioner over key decisions relating to the Games.

Sir Ian is certain to face tough questions about the crisis today when he faces a full meeting of the police authority, with Boris Johnson, the Mayor of London, in attendance.

Mr Ghaffur was at the Association of Chief Police Officers conference in Liverpool last night. He told The Times: “I’m not able to say a word. I can’t comment.”

In a statement issued yesterday, Scotland Yard said that it was “unaware that an employment tribunal application has been served or is in the process of preparation”.

It added: “If it is, we regret and are disappointed that Assistant Commissioner Tarique Ghaffur has chosen to pursue such a course. AC Ghaffur is a respected senior police officer who has achieved a great deal.

“We have respect for his experience, skills and achievements. We are keen to listen to any concerns that he has and attempt to resolve them with him. Any suggestion that the commissioner will not speak to AC Ghaffur is absolutely untrue.”

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