The figures show PCSOs hand out fines for anti-social behaviour, public disorder or motoring offences at a rate of one every four month.

The figures state that forces where PCSOs failed to detect any offences include Northumbria, the West Midlands, which has 644 officers, and Nottinghamshire, which is served by 217 PCSOs.

The Police Federation's Alan Gordon said: "PCSOs have been seen by some as a cheap alternative to police officers, who can make the public feel safe.

"But these figures show we were right to be concerned about what benefits they bring to the table."

In the past year the number of PCSOs nationwide has risen from 7,000 to 13,748.

PCSOs, who can earn up to £24,500 a year, have powers to detain suspects until police arrive and hand out fixed-penalty notices for a range of offences.

A Home Office spokesman said detecting crime and handing out penalty notices was not the prime function of PCSOs.

He said: "To attempt to measure their success solely by looking at the number of penalty notices and crimes they detect is to miss the point.

"Their primary role is to provide high-visibility reassurance, build confidence in communities and support police officers."