Taser stun guns used by the police for law enforcement are safe - the injury rate is low and most injuries appear to be minor, a US study finds.
Tasers are used by police officers in the UK
The electric disablers that hit their target with 50,000 volts are commonly used by US police and are increasingly being used by UK forces.
Human rights experts have expressed concern about the use of the stun gun.
But a Wake Forest University review of 1,000 US cases suggests the risk and severity of injuries is low.
Most injuries were mild, such as scrapes or bruises.
Three of the subjects suffered injuries severe enough to need hospital admission - two had head injuries suffered in falls after Taser use. The third was admitted to hospital two days after arrest with a medical condition of unclear relationship to the Taser.
Two subjects died but autopsy reports suggested neither death was related to the Taser.
Interim results on 597 of the cases were published in Annals of Emergency Medicine in September.
Lead researcher Dr William Bozeman, who received funding from the US National Institute of Justice for the work, said: "This is the largest study to date and the first to detail the medical effects of Tasers under real-world conditions.
"These results support the safety of the device. The injury rate is low and most injuries appear to be minor."
He stressed, however, that the Taser was a weapon and could clearly cause injuries and even deaths.
Amnesty International says Tasers have been linked to more than 70 deaths in America.
When Tasers are fired, two metal barbs connected to the weapon by a thin wire pierce the skin before the charge is delivered.
In the UK, police officers who carry guns have also carried Tasers since 2004. In September 2007, the Home Office extended permission to non-firearms officers in pilot areas.
Amnesty International's Arms Programme Director, Oliver Sprague, said: "Let's not be misled here. Tasers are dangerous electro-shock weapons.
"This is why we are urging the Home Office to review its decision and to ensure that only specialist firearms officers use the Taser in very limited circumstances and only as an alternative to shooting a lethal weapon."
A Home Office spokesman said: "The risk of life-threatening and other serious injuries is considered to be low.
"Tasers have contributed to resolving incidents without injury where otherwise there would have been a real possibility of someone being shot and killed.
"In some cases they have not needed to be fired: drawing them or arcing the Taser has been enough of a deterrent."
In England, a Taser has been used (drawn or fired) in service by the police 851 times, since April 2003.