By Danny Shaw
Home affairs correspondent, BBC News
A source alleges Mrs Crawford was "out to get" an ex-Met assistant commissioner
An independent investigation has begun into claims against Catherine Crawford, chief executive of the Metropolitan Police Authority, the BBC has learned.
The Metropolitan Black Police Association (MBPA) has alleged that she discriminated against black officers and did not carry out duties properly.
A spokeswoman for the Metropolitan Police Authority said it had "full confidence in its chief executive".
It took London's mayor three months to set up the inquiry, it has emerged.
The MBPA says it has been concerned "for some time" about the conduct of Mrs Crawford, who has been working for the authority since it was established in 2000.
In legal papers submitted to investigator Anthony Allen, the MBPA accuses her of a "failure to truly hold to account" the senior members of the Met over race and religious discrimination and equality of opportunity.
The MBPA alleges that Mrs Crawford was "reluctant" to investigate race discrimination complaints made by her own staff against senior white officers.
But it says that when allegations are made against senior ethnic minority officers she pursues them more rigorously.
The legal documents, seen by the BBC, suggest that evidence will be submitted from someone close to Mrs Crawford of an alleged "plot" against Commander Ali Dizaei, president of the National Black Police Association.
The source - who has not been named - allegedly warned Mr Dizaei that Mrs Crawford and the police authority were "out to get" him and Tarique Ghaffur, the Met's former assistant commissioner.
Mr Ghaffur was involved in a bitter race row against the Met in 2008, which culminated in his departure.
Mr Dizaei - who has had a controversial police career - is facing a criminal trial over allegations of perverting the course of justice and misconduct in public office.
The charges relate to an incident in July 2008 when Mr Dizaei arrested a man outside a restaurant in London.
The MBPA also claims that Mrs Crawford has not fulfilled her responsibility in implementing policies on race and equality.
In a statement, the police authority said: "The MPA has a formal process to deal with complaints against members of staff.
"On 13 January 2009, a complaint was formally recorded by the MPA Complaints Officer. An independent investigating officer was appointed.
"As this is an ongoing internal staff matter it is not appropriate to discuss further.
Ali Dizaei is facing a criminal trial over alleged misconduct
"However, the MPA retains full confidence in its chief executive, Catherine Crawford, and will not be commenting publicly in detail on the complaint."
The MBPA has also made allegations against David Riddle, the authority's former deputy chief executive and solicitor, who left in 2008.
Mr Riddle declined to comment, saying: "I will make my answer to the complaint, when required, to the MPA's investigator."
The complaints against Mrs Crawford and Mr Riddle were first set out in a letter to Boris Johnson, London's Mayor, in December 2008.
Mr Johnson, who chairs the police authority, replied the following month saying that the matter was being dealt with by Jane Harwood, the assistant chief executive.
Mrs Harwood said that she was "minded to stay the complaint" against Catherine Crawford because it overlapped with other proceedings involving the Black Police Association.
The MBPA hit back, writing that it was "outrageous" that Mr Johnson had delegated the complaint to Mrs Harwood, Mrs Crawford's deputy.
Eventually, in March 2009, Mr Johnson wrote back to the MBPA noting its "deep concern" about Mrs Harwood's involvement and saying that he had appointed Anthony Allen, an independent investigator, to deal with the matter.