Zayat Stables will scratch those of its horses trained by Steve Asmussen, racing manager Justin Zayat said this morning on Twitter, pending “further investigation from our side.”

Two Zayat runners under Asmussen’s care — Skinny, at The Fair Grounds, and Selway, at Oaklawn Park — had been slated to run over the weekend.

“I been directed by [owner Ahmed Zayat] to inform the stewards to scratch all Zayat horses under the care of Steve Asmussen,” Justin Zayat tweeted.

Stable owner Ahmed Zayat made the decision in the wake of a damning “undercover investigation” by People for the Ethical Treatment of Animals (PETA).  A PETA investigator spent four months undercover in the Asmussen barn and, among other things, found that Nehro — a Zayat-owned runner who finished second in the 2011 Kentucky Derby — had had extremely painful foot problems and, according to assistant trainer Scott Blasi, should have been, but was not, retired.  The PETA video implied that Zayat had made the decision to continue running the horse despite the problems.  The horse subsequently died after colicing.

But Justin Zayat, in response to a question on Twitter, said that he had “not a clue” about the foot issues.  He added that he was “heartbroken” about it.

The Zayat operation has won more than 600 races and over $36 million, according to Equibase.  This year, Zayat Stables has won 11 of 42 starts and over $300,000.