A British boy is in serious condition after being found unconscious at the bottom of a pool on board one of the world's biggest cruise ships.

The unnamed lad was holidaying with his mother and father on the 'Independence of the Seas' in the Atlantic coast of France.

Yann Bouvard, regional maritime spokesman for Brest, told AFP the boy, "was found in a state of cardio-respiratory arrest at the bottom of the ship's pool".

The ship's doctor was able to restart the boy's heart.

He was taken to hospital by a French navy helicopter, where he is described as being in a "serious" condition.

The ship's crew have described the incident as "incomprehensible".

Bouvard said: "What is terrible is that children can drown without making any noise at all. We've never had a case of a boy drowning in a pool on a ship before, but we have unfortunately a lot of experience of that happening in pools on land, and we know that it can happen to anyone, anywhere."

He asked the child's parents not to feel guilty, adding: "This sort of thing can happen without anyone realising."

The 154,000 GT 'Independence of the Seas' is part of Royal Caribbean International's fleet. It boasts fountains, waterfalls and a water play park, and is manned by 1,360 crew. A one-week cruise for two costs around £1,000.