A teenager emerged from a beach in Australia with blood all over his legs after tiny sea bugs “ate through his skin”, leaving marine experts struggling to solve the identity the mysterious creatures.

In an incident likened to a scene from a horror film, Sam Kanizay, 16, went to Brighton beach in Melbourne on Saturday and spent 30 minutes standing in the water to sooth his legs after a football game. When he walked out, his legs were covered by creatures that are believed to be some form of flesh-eating bug.

"I walked out and saw what I thought was sand covering my calf and shook it off, and by the time I'd walked across the sand …. I looked down and noticed I had blood all over my ankles," he told 3AW Radio.

"It took a while to get all the blood off and it came back pretty quickly… It sort of looked like hundreds of little pinholes or pin-sized bites distributed all over my ankle and the top of my foot.”

Jarrod Kanizay, Sam’s father, said his son was calm and not in any pain. But the family rushed him to hospital when it became clear that the blood “wasn’t washing away”.