Santa Anita Park has cancelled horse racing indefinitely after the latest in a series of horse fatalities at the renowned track.

The track has now suffered 21 fatalities in racing and training since the winter meeting began on December 26.

Santa Anita also announced it had hired Dennis Moore, the former track superintendent, as a consultant to help lead a study of the track surface and the California Horse Racing Board is also investigating the matter.

The announcement of the suspension comes as the track was set to host a big racing weekend featuring the Santa Anita Handicap for older horses and the San Felipe Stakes for three-year-old Kentucky Derby hopefuls.

Mick Peterson, an expert from the University of Kentucky on surfaces, was brought in last week to examine the track.

"If you can't figure it out, you have to quit racing," Peterson told the Los Angeles Times.

"I've told (racing secretary) Steve Lym, keep testing until we know what's going on. We're all in. We're going to figure it out."