Panicked swimmers were seen racing to escape a shark – only to realise they were running away from a tuna. 

Footage taken at Ancon Beach on Marbella’s Golden Mile showed the huge fish thrashing around near the shore. 

From a distance, the fish appeared to be a shark and a beachgoer was seen trying to outswim it in a panic. 

Others were seen running towards it, hoping to catch a glimpse.  

The fish turned out to be a 650lb tuna, which thrashed around in the shallow water trying to get back out to sea as more and more people arrived.

The water around it turned red as the tuna, which was bleeding from its gills and is thought to have been injured by fishing gear or a jet-ski, moved around violently in the water.

Once it became clear it was harmless and in difficulties, beachgoers are said to have helped it return to deeper water using sun beds and deck chairs to push it back out.

The nationality of the swimmer who had a scare when he went for a dip was not clear this morning.

Footage taken at Ancon Beach on Marbella’s so-called Golden Mile showed the huge fish thrashing around near the shore

A beachgoer was seen trying to outswim it in a panic

The monster sea creature turned out to be a giant 650lb tuna which thrashed around in the shallow water

From a distance, the fish appeared to be a shark

Camilo Orosa, a Marbella-based local commenting on the scenes, said: ‘My God, if it were me, I would already have s*** my pants, or rather my swimming trunks.’

Another social media user added: ‘If I was that swimmer I would have died from a heart attack. It looks like a shark.’

He added, referencing the classic 1975 thriller about a great white by Steven Spielberg: ‘All that was missing was the music from Jaws.’

Jade Bloomberg, a British expat who runs a Marbella-based electric water sports and wellness company, said: ‘It was in so much distress, I went into the water to see if it was tangled in a net or if it had something inside but nothing. It was huge, so beautiful.’

Another social media user said: ‘That poor tuna must have had some kind of collision with a jet ski or something similar.

‘Tuna being around is normal and they tend to stay close to the coast. Sometimes they get mistaken for dolphins.’