Tarique Ghaffur claims he was discriminated against by the Met
The UK's top Asian police officer is to accuse Met Police chief Sir Ian Blair of ordering the rewriting of a report on officers' harassment of a black man.
The claim is in documents handed to an employment tribunal into Assistant Commissioner Tarique Ghaffur's claims of racial and religious discrimination.
It relates to Mr Ghaffur's report into why the man was stopped 37 times and charged 17 times but never convicted.
Scotland Yard said it would not comment before the employment tribunal started.
Mr Ghaffur is taking legal action against Sir Ian and a junior colleague, Deputy Assistant Commissioner Richard Bryan.
He is alleging that he was effectively sidelined by Sir Ian.
Among the pages of complaints, Mr Ghaffur says he was asked to carry out an investigation into why a black man, Delroy Lindo, was stopped 37 times and charged with 17 offences but never convicted.
The employment tribunal claim says Mr Ghaffur's conclusion that Mr Lindo was a victim of harassment was unacceptable to Sir Ian.
Mr Ghaffur says he was asked by Sir Ian to withdraw the findings. When Mr Ghaffur refused he says it was rewritten by a third party and he was not permitted any further involvement in the case.
The employment tribunal is expected to take place next year.