Scientists yesterday explained how they had bred Britain's first test-tube horses in the hope of boosting the nation's chances of winning Olympic equestrian medals - and preserving endangered species.

Two male foals - produced using artificial fertilisation techniques more commonly associated with the creation of humans - were born at a specialist research unit in Newmarket, in the past few weeks.

However, the head of the team behind the experiment said the first cloned horse was still a long way off - although he would have no objections to such a development.

Staff at the Equine Fertility Unit, which is privately funded, hope the birth of Ic-Xhie and Quick-Xhie will lead to the production of greater numbers of stronger, fitter and faster horses for showjumping and three- day events

The move was welcomed by the British Equestrian Federation, but animal welfare campaigners said they were disturbed.

There are no plans to create test-tube foals for racing.

A spokeswoman for the Equine Fertility Unit said the birth of the foals was the culmination of a two-year project by Chinese embryologist Xhie Li.

She said the development of the technique would enable top-class competing equestrian horses to be bred from while they were still at their peak.

"With luck, Britain will have a gold medal winning horse produced using this method at the 2012 Olympics," she said.