A Thai navy SEAL who took part in the dramatic rescue of 12 boys and their soccer coach from a flooded cave in northern Thailand last year has died from a blood infection he contracted during the operation.

Petty Officer Beiret Bureerak had been receiving treatment, but his condition worsened, the Royal Thai Navy said in a statement on Friday.

Another rescuer, former navy diver Sergeant Saman Kuman, died during the rescue operation.

Wild Boars Academy’s coach Ekapol Chanthawong and 12 boys had gone to explore the Tham Luang caves in Chiang Rai province on June 23, 2018, when a rainy- season downpour flooded the cave system and trapped them underground.

They survived for nine days on water dripping from rocks before they were discovered.

Volunteers from abroad, including Australia, joined the rescue effort, which ended on July 10 when the boys and their coach were all brought out safely.

Nineteen divers helped to escort the final members from the cave after the tough and dangerous rescue.

Last month the Thai cave reopened a year after the young soccer team became trapped.

Officials from the Tham Luang National Park said at least 2000 tourists arrived at the park to be among the very first to see the Tham Luang cave as it reopened to the public.

This year it was revealed that in order to remove the boys from the cave safely, they were drugged with ketamine and handcuffed.

ABC Australia Southeast Asia correspondent Liam Cochrane wrote in his book The Cave:

“To calm nerves, the parents were told the boys were being taught how to dive and the media reported that each of them would be tethered to an air hose and then swim out with one rescue diver in front and another behind. This was untrue.

“Those who had been inside the flooded tunnels knew there was no way a child who had never dived before could make it through the muddy and treacherous obstacle course.

“The only hope was to sedate them, put oxygen-fed masks with silicone seals over their faces and let the expert cave divers carry them out,” Cochrane wrote.

“But it was crucial that the masks fitted tightly, otherwise they might drown.”