LONDON (Reuters) - Two policemen fired powerful new electric stun guns that have yet to be officially approved at fugitive gunman Raoul Moat at around the time he killed himself after a six-hour standoff, investigators said on Tuesday.

Murder suspect Raoul Thomas Moat is seen in an undated photograph provided by Northumbria Police force in Newcastle. REUTERS/Northumbria Police/handout

The Independent Police Complaints Commission, investigating the 37-year-old’s death, said it was unclear whether police delivered the shocks before or after Moat shot himself.

Two officers from the West Yorkshire force shot Moat with an XRep Taser, a wireless round fired from a shotgun that delivers a shock designed to incapacitate.

“This is understood to have been in an effort to prevent Mr Moat taking his own life,” the IPCC said in a statement. “The precise sequence of events regarding the discharge of the Tasers has not been established.”

The former bodybuilder and nightclub bouncer, who bore a grudge against police, went on the run for six days after shooting his former girlfriend, her boyfriend and a policeman.

Armed officers surrounded him on a riverbank in the town of Rothbury in Northumberland where he had been living rough.

Opening the inquest into Moat’s death, Newcastle coroner David Mitford said he had died from a gunshot to the head.

The Home Office said it was still testing the XRep Taser and had not yet approved the device for use by police.

“However, legally, police forces have discretion to use any equipment they see fit as long as the use of force is lawful, reasonable and proportionate,” it said in a statement.

Police in England and Wales have used a form of Taser since 2003, although those devices are smaller handheld guns which fire an electric wire at suspects from a closer distance.

Moat’s brother, Angus Moat, said the police were wrong to use Tasers on a man lying in the rain holding a gun.

“He’s going to go into muscle spasm. He’s going to have an involuntary reaction and pull the trigger, and he’s going to die and he might not necessarily have ever wanted to,” he was quoted as saying in the Daily Mail.

Northumbria Police’s Temporary Chief Constable Sue Sim said officers strived throughout the standoff to persuade Moat to give himself up peacefully. In a statement, she said police did fire Tasers, although she gave no details of the timing.

Moat’s gun went off at 1:12 a.m. on Saturday morning, at around the same time as the Tasers were fired, the IPCC said.

“Investigators will obtain evidence from the officers and negotiators who confronted Mr Moat,” the watchdog said. “The review of tactics will consider the deployment and use of the XRep Taser.”