Kaushik Patel, a resident of US state of Illinois, is suspected of dousing Om, 4, and Vishv, 7, in gasoline and setting them afire at their home in Glendale Heights on November 18 when their mother was away.

Om, who suffered serious burn injuries, died on Thursday after battling for life for two months at a hospital.

His father, who also suffered burns, will be arrested and charged with first-degree murder and aggravated arson once he is released from the hospital, which could be next week, said DuPage County State’s Attorney Joseph Birkett.

“We’ve alerted the (police) chief and the jail’s medical staff to be ready for him,” Birkett was quoted as saying by Chicago Tribune.

Om died the same day as a blood donation drive in the brothers’ name was launched.

Vishv remains in critical but stable condition in the burn unit, said a hospital spokesperson.

The boys’ mother, Nisha Patel, was granted an order of protection on December 18 to keep Kaushik away from the children, and it was extended for another month on Jan 10.

Police, who have been maintaining around-the-clock security at the hospital, were hoping to interview Om, but he never regained consciousness after doctors placed him in a drug-induced coma.