A 19-year-old remains in a critical condition in hospital after he held a loaded revolver to his head and pulled the trigger in a game of Russian roulette.

Police have been told Sydney teenager Josh Taylor was sitting in a car with his friends outside the IGA supermarket in Pitt Town in Sydney’s north-west on Friday night when he shot himself.

“We are aware a 19-year-old male received a serious gunshot wound to the head after reports he was … playing Russian roulette with a loaded revolver,” Detective Inspector Garry Sims told reporters.

The Smith & Wesson firearm discharged in the side of Taylor’s head above his ear.

He was taken to hospital where he remains in a critical but stable condition. The gun is being examined by experts.

Taylor’s mother posted on Facebook at the weekend: “Come on son … please please fight like you always have … no words can explain how desperate we are for you to just hang on and fight.”

There was no evidence that anyone else in the car was involved in the game apart from Taylor, Sims said.