The Police Complaints Authority (PCA) expressed concern about the unjustified use of the spray as it released the figures in its annual report.

BBC Home Affairs Correspondent Jon Silverman: "Police say that new guidelines are needed"

The PCA revealed that 476 people complained about the use of CS sprays in 12 months.

More than half the cases involve use of the spray in enclosed circumstances - such as in homes, pubs or cars.

All but three forces in England and Wales now equip their officers with CS spray. As its use has increased, so has the number of complaints.

John Giffard of ACPO defends the use of CS spray

CS was intended primarily for use in self-defence, but there is concern that it is frequently deployed as a method of restraint or control rather than when an officer is in genuine danger.

Controlling and restraining suspects

In nearly half of the cases, complainants claim the spray was not used in self defence but to control or restrain suspects.

"Although this can be a legitimate use of CS spray, the spray was introduced primarily for use by officers in self-defence," the report said.

"It had been used in a variety of ways to contain situations: where people were still struggling, having been restrained; where there was a perceived threat of violence, to stop people interfering with another's arrest; and, in one or two cases, to prevent suspects running away."

About one-third of the complainants allege that the spray was used at a distance of less than 3ft. The recommended safe range is between three and 15ft.

CS spray temporarily disables a person who has been sprayed, causing streaming eyes and nose and breathing difficulties. The side effects usually last a few hours. The report says there is no proof that the spray causes permanent damage.

'Situations defused by CS'

The PCA is also concerned about the effect of CS on people taking drugs, although no complaints have so far involved permanent damage caused by the spray.

And new police guidelines are to be issued on the use of CS against people with mental health problems.

Mental health charity Mind has been calling for the use of CS spray on mentally ill people in their homes and on hospital wards to be restricted.

It has written to the Department of Health expressing concerns about the possible interaction between the chemicals in the spray and psychiatric drugs.

It welcomed the call for increased police training.

The Association of Chief Police Officers (ACPO) says it has no doubt about the advantages of CS sprays.

John Giffard, of the association's self-defence committee, said police officers armed with CS spray felt better protected.

"In many cases, situations are defused by the mere presence of CS," he said.

Big rise in disciplinary charges

The PCA also revealed it recommended 333 disciplinary charges should be brought against officers in 1998-99 - a rise of 41% on the previous year.

Another 861 other disciplinary actions were taken, including admonishments.

A record 194 cases were referred voluntarily to the PCA, including 65 deaths in police care or custody, 29 road traffic incidents involving police vehicles and nine firearms incidents.

The Crown Prosecution Service brought charges against 28 officers as a result of public complaints, compared with 18 in 1997-98.

One in three corruption allegations, one in five accusations of sexual assault and one in five allegations of failures in duty led to disciplinary action being taken.

Eleven per cent of complaints against police came from blacks and a further 5% from Asians.