Ali al-Shamarani is alleged to have paid PC Ghazi Ahmed Kassim, 52, to obtain confidential information from police computers about people with Middle Eastern connections living in the UK.
Mr Shamarani has returned to Saudi Arabia and a constable has been arrested and charged after an investigation by Scotland Yard anti-corruption officers. It is understood the diplomat was not arrested because he was likely to claim diplomatic immunity.
The claims of misconduct come at a time of difficult relations between the UK and Saudi Arabia, with BA flights cancelled because of an apparent terrorism threat and a continuing row about the ill-treatment of Britons who were held in Saudi jails on bomb charges.
Mr Shamarani is alleged to have had a four-year corrupt relationship with PC Kassim, who was based at Hammersmith and Fulham, west London. It is claimed that the diplomat "tasked" the officer to discover with finding information on named individuals living in the UK.
PC Kassim is alleged to have accessed computer systems - including the police national computer - then passed information to Mr Shamarani.
The case is one of a number in which officers and civilian workers in the force have been charged with leaking information as a result of investigations by specialist squads of detectives.
A Foreign Office spokeswoman said yesterday: "We have spoken to the Saudi ambassador and asked for a diplomat to be withdrawn from the UK. In response to that request the diplomat was recalled and is no longer accredited to the Saudi mission in London."
A switchboard operator at the Saudi embassy said she thought Dr Mr Shamarani was on holiday, but added that a colleague of his would call back. After four hours, the call was still unreturned.
PC Kassim was arrested and suspended on July 16 and charged with misconduct in a public office contrary to common law. He appeared at Bow Street magistrates court the next day and was given bail. His next appearance was last Wednesday at an Old Bailey court sitting at Blackfriars crown court in south London.
The charge alleges that between 1 January 1999 and 8 February 2003 he gained unauthorised access to computer programs or data.
It states that he had "diverse meetings and conversations" with Mr Shamarani and received payment in exchange for the information supplied "and thereby did harm the public interest".
