Raoul Moat. Photograph: Northumbria Police/PA

The director of operations at the company which supplied the Tasers used by police in their standoff with the gunman Raoul Moat has died in a suspected suicide, it emerged today.

Peter Boatman, 57, was a Northamptonshire police inspector before becoming a partner in Pro-Tect Systems eight years ago. The home secretary, Theresa May, revoked the company's licence on Tuesday, announcing it had breached its conditions by supplying X12 Tasers directly to the police. The licence gave the firm permission to supply the stun guns only to the Home Office's science and development branch for testing.

The Home Office also said Pro-Tect breached "rules governing the secure transport of the devices and ammunition". The move meant that Pro-Tect, the only supplier of Tasers in the UK, was no longer able to import and sell the devices. The Home Office stressed that the police could use any weapon they saw fit as long as its use was lawful, reasonable and proportionate.

Boatman said he had been shot more than 200 times while testing Tasers.

Boatman's business partner said last night he had been "destroyed" by the criticism of him supplying police with Tasers. Kevin Coles, Pro-Tect's managing director, said: "He knew there was something there that would offer the officers protection and that was what his motive was.

"The furore over it destroyed him."

Northamptonshire pPolice conducted an inquiry into the supply of the devices following reports that the Tasers fired at Moat during the six-hour standoff in Rothbury, Northumberland, were not licensed. Their report was submitted to May.

Moat went on the run in July after shooting his ex-girlfriend, killing her boyfriend and blinding a police officer. Firearms officers fired two Tasers at him in an "effort to stop him taking his own life", the inquest into his death was told. The standoff ended when Moat, 37, shot himself.

The Independent Police Complaints Commission investigation into the circumstances of Moat's death is continuing.