Race horse trainer Andy Turnell has spoken of his horror when one of his horses, the promising jumper Marching Song, died in front of him as he paraded for Saturday’s first race at Newbury.

Marching Song and a second horse, Fenix Two, died within seconds of each other and are believed to have been electrocuted by an underground cable.

Another horse due to take part in the opening race, Kid Cassidy, was withdrawn after stumbling and a fourth horse, Merry Giant, was said to have been “badly traumatised”.

Broad Hinton based Mr Turnell, son of the late Marlborough racing trainer Bob, said he was a few paces from five-year-old Marching Song when the horse collapsed.

He said: “My head travelling lad (Colin Pritchard) went straight to him as he lay on the ground and he said he felt a tingling in his hands.”

However Mr Turnell, who helped remove the horse’s head collar, said he did not feel anything himself and added: “We both thought the horse had a heart attack.”

Mr Turnell had been training Marching Song, owned by a four-strong consortium, for about a year.

“He was a very nice young horse and had a good future in front of him,” he said.

The trainer said he had heard nothing from the racecourse, where racing was abandoned for the day, but added: “It look s certain that he was electrocuted.”

Racecourse joint managing director Stephen Higgins said there was “a distinct possibility” that pre-race maintenance had disturbed a cable that had been buried for at least 40 years.