British horseracing's governing body has confirmed that the two horses that died at Newbury last weekend were killed by heart attacks as a result of accidental electrocution.
An investigation by the British Horseracing Authority found that Fenix Two and Marching Song collapsed in the paddock before Saturday's first race as a result of "leakage of electricity from a cable."
A post-mortem examination says no suspicious circumstances have been detected.
The two horses collapsed and died in the parade ring amid fears they were electrocuted. The reasons for the deaths of Fenix Two and Marching Song before Saturday's first race were not immediately announced by officials at the southern England course.
Professor Tim Morris, director of equine science and welfare for the BHA, says Thursday the findings are "all consistent with the cause of death being accidental electrocution."
The course has been cleared to hold meetings again after the electricity cable beneath the paddock was disconnected and removed Sunday.