Image caption Sorry folks, it's just a costume

There is no evidence that mermaids exist, a US government scientific agency has said.

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.

"No evidence of aquatic humanoids has ever been found," the service wrote in an online post.

The National Ocean Service - a division of the National Oceanographic and Atmospheric Agency (NOAA) - posted an article last week on its educational website , Ocean Facts.

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, the service wrote.

The article was written from publicly available sources because "we don't have a mermaid science programme", National Ocean Service spokeswoman Carol Kavanagh told the BBC.

She said that at least two people had written to the agency asking about the creatures.

The inquiries followed May's broadcast of Mermaids: The Body Found , on the Discovery Channel's Animal Planet network.

The programme was a work of fiction but its wink-and-nod format apparently led some viewers to believe it was a science education show, the Discovery Channel has acknowledged.