The top police officer in Richmond is also a co-director of a private police training company, it has been revealed, despite strict Metropolitan Police rules about outside business affairs.

Borough commander Parm Sandhu is listed as co-director of Rod Jarman Associates (RJA), which offers clients “advice, training and development to all aspects of policing”.

The firm has worked with Zayed University, the Abu Dhabi police force and Al Darak management consultants in the United Arab Emirates, as well as the Prince’s Trust and St John Ambulance.

The Metropolitan Police’s rules state officers should not have outside business interests which are “incompatible” with their professional responsibilities.

Interests which are almost always ruled out include any activity using specialist police skills or knowledge, working as a consultant or instructor for firearms or tasers, and those which “mirror any form of police activity”.

Chief Superintendent Sandhu has been registered as co-director of RJA since 2010 alongside her partner Rod Jarman, who was formerly a deputy assistant commissioner with the Met.

Metropolitan Police said it has “full confidence” in Chief Superintendent Sandhu, who is its highest-ranking female Asian officer, and has no concerns about any of the previous roles she has filled within RJA.

A police spokesman confirmed she has registered her business interests.

Tangentially, in 2010 reporters were told a home in Abridge, Essex owned and being let by Mr Jarman had been turned into a cannabis factory.

The criminals ran up a £20,000 electricity bill for lighting to grow thousands of “super strong” skunk plants.

But a Sunday Times investigation actually showed the house was owned by Chief Superintendent Sandhu between 2006 and 2013.

A police spokesman said the matter had been “swiftly and correctly” recorded internally, and the force felt there was no need to take action.