More than 23,000 police officers and staff are moonlighting in second jobs, with the figure soaring nearly 20% in a year, it has been reported.
The figures mean more than one in 10 officers in England and Wales earn a second income from non-police work, according to an investigation by the Mail on Sunday. At the same time, the number of investigations into potential rule breaches has tripled, raising questions over conflicts of interest arising from second jobs.
Some officers may work in self-defence training, for example, therefore meaning police forces may be commissioning off-duty staff to carry out such work for them, the report claimed. A total of 23 of England and Wales's 44 forces did not check to see if they were paying companies run by their own officers for work.
Police staff are allowed to take second jobs or run companies if approved by their superiors. Unless there is a direct conflict of interest, permission is likely to be given.
The Mail on Sunday studied figures provided by Her Majesty's Inspectorate of Constabulary and found that at least 23,043 police staff had second jobs out of a workforce of 201,575 in May 2012. That was up 19% from March 2011 figures, which showed 19,329 had second jobs.
The number of investigations into second jobs soared in the nine months to May, with 154 reviews carried out - more than 17 a month. In the previous year, 82 - fewer than seven a month - were carried out.
A Home Office spokesman said: "It is the responsibility of chief constables to ensure that any secondary jobs held by officers do not harm the public's perception of the police or result in any conflict of interest. The Home Secretary will put new proposals ensuring the highest standards of integrity in the police to Parliament in the new year."
The news came as a senior Labour backbencher warned that public confidence in the police force has been shaken due to a "dangerous cocktail" including the "plebgate" affair and the results of the Hillsborough Inquiry.
Keith Vaz MP, chair of the Home Affairs Select Committee, which will begin an inquiry into police accountability, integrity, internal corruption and malpractice next month, said it is a "defining moment" for the service. He called on Prime Minister David Cameron to host annual summits with senior officers, and called for "a new Magna Carta" for policing.
Writing in the Sunday Express about the alleged altercation between former chief whip Andrew Mitchell and police officers at the gates of Downing Street, dubbed "plebgate", Mr Vaz said: "Take a police officer apparently masquerading as a member of the public, a confidential log book finding its way into the public domain, add the results of the Hillsborough Inquiry, which have resulted in thousands of serving and former police officers being investigated, and the fact that 26 out of the 43 police forces do not have a permanent chief constable, and you have a dangerous cocktail."