One year after 12 boys were incredibly rescued from a flooded Thai cave, a hero diver has returned to the site and found haunting messages left by the kids.

Mikko Paasi, 44, was stunned to find carvings spelling out children's names and the words "lost boys" after digging his way into the dark chamber where the youngsters were found.

Mikko was one of more than 90 divers - including seven Brits - who saved the kids and their football coach after a shock monsoon trapped them inside the cave for an agonizing 18 days last summer.

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It turned out to be one of the most dangerous rescues in history.

Now, as Thailand marks one year since the last of the boys was brought out alive, Mikko exclusively tells Sun Online how he helped save the youngsters against all odds - and how he has been back to the site and uncovered hidden carvings and other lost relics.

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"It was intense," he says.

"We found a boy had carved his Facebook address on the wall. We found markings in Thai like '13 boys lost'... and then there were dates like June 26."

Members of the Wild Boars soccer team pose for a photo during their return to the Tham Luang caves, where they were trapped in a year ago, in Chiang Rai, Thailand, June 24. (REUTERS)

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