The male seahorse was just hours away from giving birth to his babies

The six-inch (14cm) male spiny seahorse Hippocampus guttulatus was within hours of giving birth when it was spotted off Purbeck in Dorset on 26 July.

The exact location is being kept secret, to stop potential sightseers from disturbing the new babies.

Seahorses are unique as the male becomes pregnant, carrying babies in a pouch on his belly before giving birth.

The spiny seahorse, one of two species found in Britain, is coloured to blend in with seaweed, which means it is rarely spotted.

We couldn't believe our eyes and had to surface to confirm what we had actually seen Julie Hatcher, diver

Conservationist Julie Hatcher and underwater photographer Steve Trewhella, who found the creature, say the sighting is important as it shows the creatures are breeding on the south coast.

Ms Hatcher, who works for the Dorset Wildlife Trust as manager of the Purbeck Marine Wildlife Reserve, said "We couldn't believe our eyes and had to surface to confirm what we had actually seen.

"Then it was straight back down to have a good look and take some photos before we left it to find a suitable place to give birth."

"The Seahorse Trust were thrilled to bits because it proves seahorses are breeding here and they are not just occasional visitors."

Mr Trewhella added: "This is the first pregnant one that's ever been seen or photographed.

"They are rare anyway, so I didn't think I would see a pregnant one into the bargain."

Seahorses are under threat from scallop dredgers and sailing, as boat moorings can destroy their habitat.

They are also collected for use in oriental medicine.