A British Horseracing Authority (BHA) investigation has concluded the deaths of two horses at Newbury were caused by "accidental electrocution".
Fenix Two and Marching Song died in the paddock on Saturday and post-mortems revealed both suffered heart attacks - no suspicious substances were detected.
An electricity cable which ran beneath the parade ring has since been disconnected and removed.
The BHA has confirmed Friday's rescheduled meeting can go ahead.
Professor Tim Morris, director of equine science and welfare for the BHA, said: "The authority has been officially informed that there was leakage of electricity from a cable under the parade ring in the area where the incident occurred.
I would like to stress again that Southern Electric has confirmed that there was no danger to the public on Saturday
Newbury joint managing director Stephen Higgins
"There was immediate veterinary attention, and our inquiry on the day noted the racecourse veterinary surgeons felt a tingling sensation when examining the horses, and that the veterinary surgeons noted particular clinical signs such as muscle contractions.
"Both horses that died, Marching Song and Fenix Two, have undergone post-mortem examinations which showed sudden cardiac arrest as the cause of death.
"Samples taken from the horses affected have shown no evidence of substances that could have caused this incident.
"These findings are all consistent with the cause of death being accidental electrocution and at this stage we are not investigating any other cause of death.
"I can also confirm that, contrary to speculation, no evidence of any burn marks around the mouth was found on post-mortem examination, neither were such marks found by the veterinary surgeons on the horses at the start."
He said it was the first time a race meeting in the UK had been abandoned for "a horse-related event".
"Whilst we do not want to be complacent, at the moment I think it would be safe to regard this as a one-off and very unusual accident. I don't think we need to be digging up every racecourse and looking for buried cables," he added.
The two horses died on Saturday before the first race, which was run before the remainder of the meeting was abandoned.
Horses 'had no chance' at Newbury - Henderson
Newbury officials have assured the BHA the parade ring area is safe for use by horses and humans and that electricity cables within the racecourse are operating within required safety standards.
But energy providers Southern Electric Power Distribution are continuing their investigation to establish the cause of the leakage.
"I would like to stress again that Southern Electric has confirmed that there was no danger to the public on Saturday," said Newbury's joint managing director Stephen Higgins.
"Once again we would like to extend our condolences to the connections of those horses and will continue to liaise with those affected."
Kid Cassidy and The Merry Giant were two other horses affected by the leakage although The Merry Giant has since recovered from the incident, according to his trainer Rebecca Curtis.
The rescheduled meeting starts at 1210 GMT on Friday, when several Cheltenham Festival contenders are set to run in races including the Game Spirit Chase, the Aon Chase and the Totesport Trophy.
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