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, the Royal Thai Navy said on Friday.

Key points: A dozen boys and their soccer coach were rescued from a cave in northern Thailand in July last year

A dozen boys and their soccer coach were rescued from a cave in northern Thailand in July last year Petty Officer Beiret Bureerak is the second casualty from the rescue

Petty Officer Beiret Bureerak is the second casualty from the rescue About 80 Thai Navy SEALs took part in the mission

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

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

Sergeant Kunan died after entering the cave to lay oxygen tanks along the exit route, and at the time was the only casualty in the international operation.

About 80 Thai Navy SEALs, who made up the bulk of the divers involved in the rescue effort, took part in the mission.

Petty Officer Beiret Bureerak had been receiving treatment after the cave rescue in northern Thailand. ( Facebook: Royal Thai Navy )

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, drinking water dripping from rocks before they were discovered.

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

ABC/Reuters