Swimmers have been warned to stay away from a dolphin that is becoming too amorous with humans.
Experts say that the bottlenose dolphin, which has been filmed among bathers in Cornwall and has been named Nick by locals, is displaying signs of "sexual aggression" and had to be lured back out to sea after thrashing his tail at swimmers.
TV naturalist Chris Packham told The Sun newspaper: "Dolphins play with interesting things in the water and this can include people.
"They can get sexually aggressive and there is a chance this dolphin could be loved-up and confused.
"Imagine you got lost and ended up in the middle of a herd of elephants. It would be pretty confusing. That's like Nick, surrounded by people - but dolphins are immensely powerful and therefore dangerous."
Katheryn Wise, of the World Animal Protection charity, added: "Lone dolphins may employ this behaviour to create social bonds.
"This behaviour can be worsened if the dolphin is increasingly habituated to people's presence. It is strongly advised to keep a safe distance in the water."