SeaWorld acknowledged on Thursday that it had sent company employees to pose as animal rights activists to protect the company “from credible threats.”

The company’s chief executive, Joel Manby, said that several employees went undercover, but that SeaWorld’s board of directors had ordered an end to the activity.

The admission came after the People for the Ethical Treatment of Animals accused a SeaWorld employee last year of infiltrating its ranks and even joining several protests against the amusement park’s system.

On Thursday, PETA’s executive vice president, Tracy Reiman, said that SeaWorld’s statement confirmed that “the company has employed more than one spy to infiltrate and agitate at PETA.”