Cooking gas leakage has been identified as the primary cause behind the explosion inside a house in Upputhara that left the homeowner seriously injured, according to preliminary findings of the police investigation.

Upputhara Sub-Inspector P N Pradeep, who is leading the investigation, said the forensic examination did not find the presence of any other explosive substances. Officials from the Fire and Rescue Services and the Electricity Department also carried out inspections on Monday.

The explosion occurred around 8 am on Sunday at the residence of M Ansari, owner of Fathima Gold Covering, at Pakkaveettil in Upputhara. The blast caused extensive damage to the house, with walls collapsing and roofing sheets blown apart. Household articles and electronic appliances inside the house were completely destroyed.

Ansari sustained severe burn injuries in the incident and is undergoing treatment in critical condition at a private hospital in Pala. Hospital sources said he suffered more than 60 per cent burns.

Police said Ansari was alone inside the house at the time of the incident. Since he suffered serious burn injuries, investigators were initially unsure about the exact cause of the explosion. Though a gas cylinder blast was first suspected, both cylinders in the house were later found intact, leading authorities to examine other possible causes before confirming that leaked cooking gas had triggered the fire and explosion.