Selangor police chief Hussein Omar Khan said Universiti Malaya Medical Centre had filed four police reports concerning the deaths of four Malaysians, two men and two women, in their 20s to 40s.

“Investigations found that all four of the deceased had attended the Pinkfish concert at Bandar Sunway, Subang Jaya, on Dec 31.

“Post-mortems were held today and the cause of death is still pending laboratory investigations. Checks on the bodies of the four deceased found no signs of external injuries,” he said in a statement tonight.

Hussein said the case had been classified as sudden death but further investigations were ongoing to determine if there was any criminal element behind their deaths, including whether they had been poisoned.

Checks on social media found that the “Pinkfish Festival” was held at Sunway Lagoon’s Surf Beach last night.