Sharks believed to be high on cocaine dumped at sea by smugglers are reportedly attacking surfers.

According to the Mirror UK, smugglers are jettisoning packages of the illegal substance, either for later retrieval or simply to escape the police.

The discarded drugs are reportedly being consumed by the unsuspecting apex predators, leading to frenzied behaviour.

Florida beaches have been particularly noted for washed-up batches of the drug.

During an investigation, marine biologist Tom Hird observed a hammerhead shark and a sandbar shark exhibiting unusual behaviour.

Hird, also known as “The Blowfish” on YouTube, teamed up with Tracy Fanara, an environmental scientist from the University of Florida, to investigate whether sharks were indeed consuming cocaine.

They dropped packages resembling bales of cocaine into the water, according to the Daily Star, which added that the sharks would then swim directly towards the packages and bite into them.

To ensure the safety of the sharks, the researchers used concentrated fish powder instead of the actual drug. Their observations and experiments off the coast of Florida Keys culminated in a documentary for Discovery's Shark Week, aptly titled 'Cocaine Sharks'.

Hird claimed in a recent documentary: "We gave them what I think is the next best thing. [It] set [their] brains aflame. It was crazy."

The scientific community, however, remains sceptical. They have yet to confirm whether these sea predators are indeed consuming the illicit substance, or how it might affect their behaviour. Dr Fanara, admitted: "We don't really know how sharks react to cocaine. It might make them more docile; it might slow down their movement..."

Researchers have also observed peculiar behaviour among the sharks. In one instance, a female shark was seen swimming "slightly on the one side, almost like she's weighted down, she's not quite level".

In another, a sandbar shark was spotted swimming in tight circles as if chasing something – but there was nothing there.