The department’s director, Shoki Hamzah, said a full investigation report had been submitted to the police for further action, Harian Metro reported.

“We have concluded our investigation and the report was handed over to the police in early January.

“Our findings show that the fire was deliberately set.

“So, we have referred the matter to the police,” he said after launching a fire safety campaign in Bayan Lepas, Penang, today in conjunction with the upcoming Chinese New Year and Hari Raya Aidilfitri holidays.

The two who died were a woman in her 50s and her adopted daughter, aged about five.

Their remains were found in the living room near the main entrance of the house, while the woman’s son, in his 20s, was found injured near the kitchen door after being pinned under a collapsed roof.

Following the incident, police arrested the woman’s son.

The case, initially classified as a sudden death, is now being investigated under Section 302 of the Penal Code for murder.