News of the probe caused stock in the company to tumble almost 14 percent on Friday.
The company has denied running a pyramid scheme. Herbalife products are not sold in stores. The company relies on a team of more than 3 million independent salespeople -- called distributors -- to sell products. Distributors are paid by commissions from sales and bonuses for recruiting new distributors.
In December, a hedge fund manager reported the vast majority of the company's distributors lose money, while a few at the top make millions from recruiting efforts.
