An investigation has been launched after a man turned into a human fireball in an incident involving a police taser.
Officers attended a disturbance when they found the man in a garden with a can of flammable liquid.
A report shows that shortly after arriving, one officer deployed a Taser on the man, named locally as Andrew Pimlott, 32.
Shocked residents near the property in Plymouth, Devon area said they heard what appeared to be an explosion on Thursday night.
Mr Pimlott was "fully on fire" in the horrific scene with one police officer bravely jumping on him in an attempt to put the flames out.
He was rushed to Derriford Hospital in Plymouth before being transferred to Frenchay in Bristol with "life changing" injuries.
Jack Fry, aged 20, was with his friend Brett Griffiths, also aged 20, at a house backing onto the property involved.
The retail worker said he heard screaming shortly after 9pm.
He said: "There were three screams. Brett opened the curtains and at first he thought the house was on fire.
"But then we saw a man, fully on fire, from top to bottom, like what you see on a film, with his arms swaying around.
"We saw two police officers appear from the side of the house. One of them jumped on the burning man and put him on the floor.
"The officers were shouting to each other and the one who had put him to the ground got an old duvet or cover and started smacking the burning man with it.
"There was steam coming off him and he was groaning. The sight was sickening.
"The officers then got a hosepipe and poured on water while we got some lights on extension leads rigged up outside.
"We heard more sirens and as the paramedics and fire crews arrived we went back inside.
"We want to say how amazing the officer was [who jumped on the burning man]. We both think this officer is, well, I would use the word hero."
Jack and Bret helped pass across buckets of water and a hose with all three emergency services involved in the operation.
Another local added: "I thought a bomb had gone off. It was a sound like a shot or a bomb. Then I heard a howling noise."
The case has now been reported to the Independent Police Complaints Commission.
A statement from the IPCC said: "The information available at this stage indicates that two police officers attended the address in Honicknowle following an emergency call from an occupant shortly after 9 pm.
"The caller advised that another resident at the premises, the 32 year old man, was in the garden with a can of flammable liquid.
"Shortly after the police arrived, the man sustained serious burn injuries and an ambulance was called. Police records indicate an officer deployed a Taser during the incident.
"The man was taken to Derriford Hospital in Plymouth and subsequently transferred to the burns unit at Frenchay Hospital in Bristol.
"His condition is described as life-changing, but is not considered to be life-threatening."
