Lengthy tests have revealed that a genetic heart defect caused a six-year-old boy to collapse and almost drown while he was on holiday in Ibiza.

Billy Gaffney, from Gaddesden Crescent, Garston, spent two minutes face down in the swimming pool at a resort in Playa d'en Bossa, Ibiza, after suddenly falling unconscious last summer.

Doctors believed the youngster's heart had stopped and tests carried out at the Royal Brompton Hospital have confirmed the youngster has the rare QT Syndrome.

His mother, Melanie, will now stage a series of fundraising events in order to buy a £1,200 heart start defibrilator machine, which will be kept at Billy's school, St Catherine of Siena, and used if he ever suffers a cardiac arrest during lessons.

Melanie, 36, said: "The risk of a cardiac arrest is never say never. It has been a very difficult time. For some children, the first time is fatal so he's a very lucky boy."

QT Syndrome is an electrical disorder of the heart, which is a common cause of unexplained sudden deaths in young people.

The condition results in an abnormally fast heart rate and when this occurs, no blood is pumped from the heart and the brain is starved of oxygen, causing loss of consciousness.

Sponsorship or donations can be sent to St Catherine of Siena School, Horseshoe Lane, Garston WD25 7HP or to the Watford Observer, Observer House, Caxton Way, Watford.