Swimmer thought he was being chased by a shark but it was a 300kg tuna

A man swimming in the shallows of a Spanish beach was given a scare when what looked like a shark chased him onto the shore – but it turned out to be a 300kg tuna.

Video footage showed a fin breaking through the surface of the water close to the beach in Marbella.

Onlookers at the Ancón beach stepped out of the water and shouted to warn nearby swimmers.

The fin then travelled quickly towards two swimmers. When one man spotted the creature,he begins to swim to the shore – but the animal followed him,causing the crowd on the beach to scream.

Onlookers gather at the shoreline to watch the spectacle,and just as the man reaches the beach,the animal surfaces,thrashing violently through the shallows.

Beachgoers were stunned to see the massive fish (Picture: SolarPix)

Sign up for all of the latest stories

Start your day informed with Metro's News Updates newsletter or get Breaking News alerts the moment it happens.But instead of a shark,a huge tuna can be seen writhing in distress. Local reporters estimated the tuna would weigh around 300kg.Later footage posted in a local Facebook group showed people helping the fish back into the sea using deckchairs and umbrellas,despite it bleeding from its gills.While sharks do live off the Spanish coast,they tend to stay far away from the beaches and spend their time hunting in deep waters.Similarly,adult tunas spend most of their time in deep water.Local reporters said that it was likely that the tuna was injured by a fishing vessel,which had caused it to become disoriented,swimming to the beach.A fear of sharks in the Mediterranean has grown after it was revealed that Great White Sharks could be breeding in the warm waters.In January,scientists said they believed great white sharks may be breeding in the Mediterranean after a juvenile was found by fishermen off the eastern coast of Spain.The large fish was filmed thrashing about (Picture: SolarPix)The creature,which was about 210cm long and weighed between 12st 8lb and 14st 2lb (80kg to 90kg) was accidentally captured on a fishing vessel.Breeding populations of great whites were thought to have disappeared from the Mediterranean some time ago,so the discovery of a young shark led scientists to investigate.They concluded that while the species remains a so-called “ghost” population in the region,it has not disappeared altogether.Great white sharks gained notoriety in popular culture after Steven Spielberg’s classic Jaws broke box office records in 1975.They are most commonly found off the coasts of Australia, South Africa and off the west coast of the US. Sightings in the Mediterranean are rare.Get in touch with our news team by emailing us at .For more stories like this,check our news page.