Ackman: HLF execs hiring own lawyers an ominous sign

Bill Ackman
Adam Jeffery | CNBC

Bill Ackman thinks shorting Herbalife is an even better short than it was when he first bet against the stock in 2012.

The most recent indicator is that senior executives at the nutritional supplement company are hiring or looking to hire their own criminal defense attorneys, the Pershing Square Capital Management founder said Monday evening at the 13D Monitor Active-Passive Investor Summit in New York.

"People are at risk of going to jail," Ackman said, noting the "very material" development.

He did not name specific "senior" executives or disclose how he knew the information, but Ackman said he was sure. The claim could not immediately be verified.