Churchill Downs on Friday said it would suspend racing as it conducts a "top-to-bottom" safety review following the death of 12 horses at the famed Kentucky track in the past month.

Racing will be halted from June 7 through the remainder of the Spring Meet, which concludes on July 3. This weekend's races will go ahead as scheduled and the remainder of the meet will be relocated to Ellis Park in Henderson, Kentucky.

Investigations by the Horseracing Integrity and Safety Authority (HISA), Churchill Downs and the Kentucky Horse Racing Commission have yet to identify a reason for the spike in equine fatalities, which overshadowed last month's Kentucky Derby.

HISA's track surface expert submitted his review of the racing surface at Churchill Downs earlier on Friday and found there were "no primary areas for concern" and that it was consistent with previous years.

Given that the surface does not appear to be the issue, animal rights activists questioned the logic of moving the races to Ellis Park.

"If the track surface was the singular cause of the rash of horse deaths at Churchill Downs, changing the racing venue might make sense," said Wayne Pacelle, president of Animal Wellness Action.

"But it's apparent that there's more at work here than track surface threats.

"We renew our request that Churchill Downs suspend its racing schedule until there is a proper forensic analysis of the horse deaths and a comprehensive plan to remediate future deaths.

"This is a response, but it feels like a shell-game response."

(Reporting by Rory Carroll in Los Angeles; Editing by Ken Ferris)