Flesh-eating ‘sea fleas’ savage teenager’s legs in bloody feeding frenzy (DISTURBING IMAGES)

A young Australian man took a dip in the ocean to soothe his legs after a day of playing football but was horrified when he returned to the beach to find his legs bleeding uncontrollably from what appeared to be thousands of tiny bites.

Sam Kanizay, 16, spent Saturday evening unwinding at Dendy Street Beach in Brighton, Melbourne when he got the fright of his life. He didn’t notice anything was wrong at first as the water was so cold – temperatures reached as low as three degrees Celsius (37°F) last week.

"When he got out, he described having sand on his legs, so he went back in the water," his father Jarrod Kanizay told the AAP.

"He went back to his shoes and what he found was blood on his legs… They ate through Sam's skin and made it bleed profusely."

The father and son rushed to Sandringham Hospital to see if doctors could stop the bleeding.

"As soon as we wiped them [his legs] down, they kept bleeding," Jarrod told ABC.

"There was a massive pool of blood on the floor."

Despite their best efforts, doctors were stumped and Sam’s legs continued to bleed, so he was transferred to Dandenong Hospital for further treatment and analysis.

Jarrod took it upon himself to try and find out what had attacked his son in the water. He took a small fishing net to the same part of the beach and returned with what looked like thousands of lice.

"We found thousands of little mite-type creatures in our net," Jarrod said, as cited by the Sydney Morning Herald.

"We put them in an Esky and brought them home and looked at them intently and let them swim in white dishes with red meat.”

"Interestingly, overnight they've essentially all clung to the meat and have been busy overnight eating it."

Once he had finished his own examination of the mysterious creatures, additional samples he took were sent for testing by marine biologists.

The flesh-eaters were identified as lysianassid amphipods, a type of scavenging crustacean, commonly known as “sea fleas.”

“It was just unlucky. It’s possible he disturbed a feeding group but they are generally not out there waiting to attack like piranhas,” Marine biologist Genefor Walker-Smith, who analyzed one of the specimens, said in a statement published by Museums Victoria.

The "fleas" release an anti-coagulant, much the same as leeches do, to prevent blood-clotting but do not possess any venomous properties and will not cause any lasting physical damage, at least.

Sam is continuing his recovery.