Police forces have been urged to stop using electric shock collars to train police dogs amid fears of cruelty.

The Association of Chief Police Officers (ACPO) called on all forces to suspend use of the collars on the advice of the RSPCA and other animal welfare groups.

The move comes during a review of all police dog training methods launched after the death of police dog Acer during training in Essex in 1997.

There was widespread public outrage when it emerged that the young dog had died after being hung up by its choke chain and kicked.

Three former officers were convicted of cruelty, one of them received a jail sentence.

Complete ban due

Eight forces are understood to be using the collars which deliver an electric shock to dogs when triggered by the handler via a remote control unit.

Pinch chains have a similar effect but rely on tightening the collar around the dog's neck instead of a shock.

The ACPO sub-committee reviewing dog training recommended taking electric collars and pinch collars off the list of approved equipment earlier this month and a ban is expected to be confirmed in April.

But Sir John Evans, ACPO president and Chief Constable of Devon and Cornwall urged forces to stop using them in the meantime.

"Police dogs are invaluable in the fight against crime and the service is committed to ensuring that the welfare of police dogs is, and remains, a paramount consideration," he said.

A spokeswoman for the RSPCA welcomed ACPO's move but urged the police to implement a total ban as soon as possible.

Forces which have used the collars recently include Cambridgeshire, Gwent, Humberside, Leicestershire, Lincolnshire, Warwickshire, West Midlands and South Wales.

A further 12 forces are understood to retain the collars but are not using them at present.