Simon James Garrick (42), unemployed, died of asphyxiation in the caravan between October 30, 2012 and October 10, 2013, after inhaling lpg, coroner David Crerar said.
''I draw to public attention the dangers of recreational substance abuse and specifically the huffing of lpg or similar gases,'' he said.
''Some gases inhaled have components which are toxic and these can cause death or disablement for this reason alone. Gas inhaled can also cause death by displacement or the oxygen content of air. Lpg in the lungs is incompatible with life.''
Mr Garrick was last seen in October 2012 and was reported missing by his family last May.
Police treated his disappearance as a possible homicide and offered a $20,000 reward in September for any information about his whereabouts.
Mr Crerar said shortly after Mr Garrick was last seen alive, he broke into a stored caravan in the Cromwell Top 10 Holiday Park and lived there for an unknown time.
He had ''huffed'' lpg from a canister in the caravan, piling blankets and clothing over the canister and his face to ensure no gas could escape.
''Simon Garrick has inhaled lpg and its effects have proven toxic and fatal.''
There was no evidence Mr Garrick inhaled the gas with the intention of ending his life and it was more likely it was a recreational substance abuse mishap, Mr Crerar said.
The caravan owner discovered Mr Garrick's body on October 10 last year after checking the caravan. The caravan's side window had been interfered with and there was food and other property strewn around the interior.
The woman found the body after pulling back a duvet on the floor. Mr Crerar said Mr Garrick was known by police to have a significant drug habit, including use of illicit drugs including rivotril, methadone, methamphetamine and cannabis.
His cellphones had not been used since the time of his last sighting and just before his disappearance he had spent about $1700, which was described as being out of character.
Senior Constable Chris Blackford, of Queenstown, gave evidence at the inquest, which was held in chambers, and said police were satisfied there was no criminal liability or suspicious circumstances surrounding Mr Garrick's death.
Because of the condition of the body, identification by the normal visual means was impossible, Mr Crerar said.
Taking into account several factors, he was satisfied it was Mr Garrick.
The CCTV footage of Mr Garrick at the last known sighting on October 30, 2012, showed him wearing the clothes found on the body and an IRD card for Simon Garrick was in the jeans pocket.
The caravan in which he was found had been stored since February 2011. Mr Crerar believed Mr Garrick died soon after the last sighting of him, although the body was not found for nearly a year. Mr Garrick's family could not be contacted yesterday for comment
on the coroner's finding.
