Thousands of police accused of corruption – just 13 convicted

Forces should not probe their own officers, says IPCC chief as shocking figures come to light

The new head of the Independent Police Complaints Commission (IPCC) has questioned the ability of forces to investigate their own officers for corruption after it emerged that more than 8,500 allegations of wrongdoing resulted in just 13 criminal convictions.

Officers – including some from the most senior ranks – were accused of crimes including rape, the misuse of corporate credit cards and perverting the course of justice, but most cases were not substantiated and only a tiny fraction ever came to court.

Dame Anne Owers said that there was scepticism about the extent to which police officers could investigate colleagues' alleged crimes, and she demanded more resources to supervise inquiries to ensure confidence in the system. "The public is understandably doubtful about the extent to which, in this particular instance, the police can investigate themselves," she said in a report by the IPCC.

She concluded that the corruption identified over the three years to 2011 was not endemic or widespread. But she accepted that it was "corrosive of the public trust that is at the heart of policing" with the number of cases increasing.

"A serious focus on tackling police corruption is important, not just because it unearths unethical police behaviour, but because of the role it plays in wider public trust," said Dame Anne, a former inspector of prisons.

The report was published just after it was announced that the IPCC – which looks into allegations of police misconduct and deaths in custody – will itself be put under the spotlight by a powerful parliamentary committee amid concerns over its record. Its investigation teams include former police officers and the Home Affairs Select Committee will assess whether it is able to carry out impartial inquiries.

The IPCC corruption report was ordered by the Home Secretary, Theresa May, because of concerns in the light of the phone-hacking scandal and the role of private investigators. The commission said that it looked at a total of 104 cases and referred less than half of those to prosecutors. It resulted in court cases involving 18 officers, with 13 of them convicted.

The highest ranking officer convicted was Ali Dizaei, the former Metropolitan Police commander, who was sacked this month after his release from prison after serving a three-year term for misconduct in public office and perverting the course of justice.

He was found guilty of framing a man in a dispute over an unpaid bill for work on his personal website in what the court heard was a "wholesale abuse of power". The report also highlighted the case of the former chief constable of North Yorkshire, Grahame Maxwell, who narrowly avoided the sack after helping a member of his family to get a job.

An examination of the cases found that substance abuse, links with criminals and dissatisfaction at work all increased the vulnerability of officers to corruption and needed to be addressed.

Policing has been punctuated by scandals over the past four decades that led to notorious miscarriages of justice including the Guildford Four and the Birmingham Six.

Deputy Chief Constable Bernard Lawson, of the Association of Chief Police Officers, said: "This report again recognises that corruption is neither endemic nor widespread in the police service. However, the actions of a few corrupt officers can corrode the great work of so many working hard daily to protect the public."