THE SHED in which a local man died had an electricity supply and was owned by Cornwall Council, it has been claimed.
Named locally as Mark 'Mack' Trudgeon, the victim had taken refuge in the fenced-off former storage shed at Coronation Park, near the boating lake.
Fire crews from Helston were called there at about 10.40pm on Saturday.
They extinguished the fire, which destroyed the building. Mr Trudgeon's body was found inside.
Police have ruled out any suspicious circumstances.
Area manager Andy Barrett, who led the fire service's investigation, said an electric heater was the most likely cause.
He said: "Prior to the fire it was cluttered inside with rubbish and an old boat, which all added to it.
"This was a tragic set of circumstances.
"There was electric to the shed. It wasn't the healthiest or safest place to take refuge. We believe the most likely cause was an electric heater too close to combustible materials."
Homeless Terry Rees was awoken nearby by a large bang and saw flames rising from the shed. He suffered minor burns to his hands and feet trying to rescue his friend.
He said Mr Trudgeon had been using the shed to shelter from the cold and rain.
Speaking at a breakfast club for the homeless at Helston's Methodist Church on Wednesday, Mr Rees said he was "still shaken" by the incident and sad he hadn't been able to do more. He said: "I had seen Mack earlier in the day. I picked him up and then he disappeared.
"I noticed the shed had been broken into at around 6pm. I checked inside and saw Mack and gave him a spare sleeping bag. There was an electric heater on. I told him to switch it off."
He said the abandoned structure was full of rubbish, including furniture and a plastic boat. The smoke would have been toxic, it would have been terrible."
Julia Wren, who runs JJ News in Coinagehall Street, said Mr Trudgeon was a regular customer and a "nice bloke".
She said: "He used to live in a house on Monument Road. He moved out last year. When he lived there he had a wife and a baby.
"Things seemed to go downhill from there. I feel sorry for those left behind."
Helston Town Council confirmed Cornwall Council owned the site and had responsibility for the park and its buildings.
Cornwall Council would only confirm it was taking part in a full investigation.