By Jon Silverman BBC home affairs correspondent

Fewer than one in five complaints against the police in England and Wales which are upheld leads to an officer being punished, according to research presented at the annual conference of the British Society of Criminology.

The conclusion made by Dr Graham Smith, of Nottingham Trent University is that the principle on which the complaints process has been based for decades is deeply flawed and should be re-thought.

His argument - supported by a number of academics - challenges the idea that by moving to a new Independent Police Complaints Commission, the government has addressed the key concern of complainants and civil liberties bodies.

The person complaining wants someone in the force to be held responsible and for that to be known publicly

Dr Graham Smith

Dr Smith says the public debate about police complaints procedures had been "obsessed" with the issue of accountability - whether the investigation process was truly independent - to the exclusion of the interests of the complainant.

He said: "The person complaining wants someone in the force to be held responsible and for that to be known publicly.

"But for chief constables, the process has been seen as a management tool to identify the rotten apple without necessarily taking appropriate action against the officer.

"This is why so many complainants prefer to go to court for compensation. What they really want is justice."

The Police Complaints Authority (PCA) does not publish figures on the proportion of substantiated complaints which lead to disciplinary or criminal action.

But a spokeswoman said one in four cases in which neglect of duty was proved resulted in "disciplinary or management" action against the officer.

New commission

Earlier in the year a leading member of the PCA said the current system of investigating complaints against the police was not effective enough to inspire public confidence.

In an interview with the BBC the deputy chairman, Ian Bynoe, said it was under-resourced and admitted mistakes were being made due to the pressure of its caseload.

A new complaints body is expected to come into force next year.

The Independent Police Complaints Commission will replace the PCA as part of the Police Reform Bill and is expected to have the power to investigate and supervise complaints at its discretion.

The IPCC will have its own investigating teams, independent from police made up of civilian managers and seconded police investigators.

The bill is expected to be enacted by November this year and will come into force in 2003.

The reforms mark a turning point in the campaign against the present system in which many minor complaints are investigated by the relevant police authorities.

But rights organisations say reforms of the PCA have not gone far enough.

The civil rights organisation Liberty argues that in practice many complaints against police officers will still be investigated by the police themselves.

Others have expressed concern the government has not yet made clear how much more money the new body will have to fund its investigations.