A US government scientific agency has said that there is no evidence that mermaids exist.

The National Ocean Service made the unusual declaration in response to public inquiries following a TV show on the mythical creatures.

It is thought some viewers may have mistaken the programme for a documentary.

Images and tales of mermaids - half-human, half-fish - appear in mythology and art from across the world and through history, from Homer's Odyssey to the oral lore of the Australian aboriginals.