Electronic records held on every police case are routinely entered late and with debatable accuracy, according to a report from Her Majesty's Inspectorate of Constabulary.
The report, which was released on Friday, found that, although 90 per cent of arrest and summons records were supposed to be entered into the Police National Computer (PNC) within 24 hours, it was taking an average of 55 days in March 2001.
By October, this had dropped to 11 days, although this figure had been adjusted to exclude three "extreme" police forces.
When the study began in March last year none of the 48 police authorities questioned was achieving targets in inputting data. In addition, the report identified serious problems in the quality of the data.
The findings are backed up by an internal Scotland Yard audit conducted by the Service Security Branch in 1999, which showed that 86 per cent of records on the Police National Computer (PNC) were incorrect.
In September, the Observer reported that spot checks into information held on the PNC about people facing prosecution had an error rate of 100 per cent in some cases.
"Anything that makes this information less than 100 per cent accurate is a cause of major concern," said Roger Bingham, a spokesman for human rights organisation Liberty.
"This is heightened by the problems with the government's Criminal Records Bureau, which is already suffering severe delays in checking teaching and nursing staff."
The report concluded that, although great strides have been made to rectify the situation, "the fear must be that the forces will resort to under-resourcing and under-achieving, to the detriment of the PNC and the force as a whole".
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