Police officers in Kent are using tasers which have exceeded their “useful life”.

The force acquired its latest batch of devices in 2009, meaning they have passed the five-year guarantee of safe usage provided by the manufacturer.

Taser International has warned other UK police forces that there is a risk of the devices not discharging the right charge.

Tasers fire two dart electrodes into a person to deliver an electric shock which causes temporary muscular incapacitation.

“Devices outside of their 5-year warranty should not deploy as instances of sudden electrical failure may increase” - Devon & Cornwall Police

Kent Police insists it carries out routine testing of its devices to ensure the highest standards of safety.

A Freedom of Information Act request discovered Home Office records state that Kent’s latest acquisition of Tasers was in 2009.

Glenn Cameron, of TSR which distributes tasers in the UK, said: “Tasers have a useful life of five years.

“We would not comment on what individual police forces choose to do after that. We would simply pass on the manufacturer’s guidance that the weapon has a useful life of five years.”

A document produced by Devon & Cornwall Police states that Taser International advises that “devices outside of their five-year warranty should not deploy as instances of sudden electrical failure may increase”.

It means that officers faced with violent offenders could find their tasers produce an electrical charge below the strength required to subdue them.

Asked whether Kent Police is concerned its devices had exceeded their “useful life”, force spokesman Glenn Pearson said: “They are routinely checked a number of times each day and there have been no issues. If there are any faults they are identified at that stage and immediately removed.”

The force says it intends to acquire new model Tasers once authorised by the Home Office.

Officers in the county drew their tasers 121 times in the first six months of this year, with a device being fired 17 times.

In the last four years officers have threatened children as young as 13 with the stun guns.

Assistant Chief Constable Jo Shiner said: “This shows just the act of drawing a taser can be enough to make offenders co-operate. All officers who carry Tasers are trained to the national standard. The use of Taser is safe, effective and reduces the risk to everybody involved, ensuring the protection of the public and officers alike.

“Every occasion a taser is discharged, a full review of the incident is carried out by Kent Police.”

The force says it has 169 tasers, but declined to say how many officers are trained to use them.

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