A teenager has been decapitated in a horror shark attack after he went swimming off the Jamaican coast.

Jahmari Reid's body was reportedly found with his head missing and his left arm bitten off.

The 16-year-old had gone spearfishing near the popular tourist town of Montego Bay on Monday, according to local police. 

The high school student vanished after going out into the water by himself and his mauled body was recovered on Tuesday. 

His heartbroken father, Michael Reid, was on the beach when divers brought his son's remains back to land.

'I can't believe that he went to sea by himself yesterday [Monday] and that was the outcome. Sad to know. I feel so bad,' he told Jamaican media.

The taxi driver said he had often tried to discourage his son from his spearfishing hobby, and that they often argued about him going out. 

Pictures from the scene showed scores of horrified locals gathering at the beach in the town of Falmouth on the island's northern coast.

Fisherman Christopher Reynolds said a group of divers had found Jahmari's body after they launched a search for him on Tuesday morning.

He said that the group had spotted a massive tiger shark near where the body was located shortly after they found a detached arm in the water.

'All of the fisherman went out there and, while they were diving to take him up, they saw the big shark. They shot at him but they didn't get him,' he told the Jamaican Observer.

He added that they hoped to find and kill the shark and locate the boy's missing severed head.