The eXtended Range Electronic Projectile (XREP) delivers a 20-second, 500 volt shock to its victims after attaching itself to its target with a series of barbed electrodes, it was reported.
Previous Tasers, a non-lethal weapon, only delivered a five-second shock, which could be retriggered and can fire darts up to 25 feet.
The new model, which went on sale in the US last month, gives off a "reflex engagement electrode" if the subject tries to grab the device, the Guardian reported.
It makers claim the weapon, which went on sale in the US last month, was a "revolutionary" step that will allow police to safely immobilise potentially dangerous suspects from a greater distance.
But Amnesty International said it was "seriously concerned".
"This is effectively a shotgun that fires electric-shock bullets," Amnesty International UK's arms programme director, Oliver Sprague, said.
The Home Office confirmed it was evaluating the XREP model for possible use in Britain.
"The Home Office Scientific Development Branch is considering it as part of their ongoing remit to evaluate new less lethal technologies" a spokesman told the paper.
The makers of the XREP, Taser International, said it was a safer way to immobilise someone than shooting them with live ammunition.
"The premise behind the XREP is not to cause or impart physical pain, it is to cause incapacitation," spokesman Steve Tuttle told the paper.
"I'm not saying this is risk free: it will leave potential bruising and it could cause a contusion.”
The use of stun guns was questioned in June when video footage in Nottingham appeared to show an officer shock a man at least twice while he was lying on the ground.
The weapons were initially only available to specially trained firearms officers but last November Jacqui Smith, the former home secretary, announced plans to fund the provision of 10,000 Taser guns nationally and training for up to 30,000 front line officers to use them.