The investigation began after a complaint was made directly to Met chief Sir Ian Blair. He is currently in the eye of a race storm with a series of racial discrimination charges levelled against him by Assistant Commissioner Tariq Ghaffur, Shabjir Hussain and Yasmin Rehman.

Commander Dizaei, in his authority as president of the National Black Police Association, had openly supported the 'victim' officers. This is the second time Dizaei has been suspended. The first was in 2001 when there were claims he had taken illegal drugs, consorted with prostitutes and was a danger to national security. The investigation, which was led by Blair, cost £4 million ($7 million). However, when the case came to trial in 2003, Dizaei was cleared by a jury in a unanimous decision.

Earlier, the most senior Asian officer in the force, deputy commissioner Tarique Ghaffur, was suspended by the police chief on disciplinary grounds. Ghaffur has filed a racial discrimination case against his chief, which is to come to hearing shortly.

Dizaei was also outspoken in his support of Ghaffur.