LIVE: Bill Ackman is hosting a webcast for his infamous Herbalife short

Billionaire activist investor Bill Ackman, the CEO of $13 billion Pershing Square Capital, is hosting a webcast on Herbalife, his infamous short position.

The webcast features a video called "The American Dream Denied: Herbalife Victims Speak Out".

"Herbalife claims it cleaned up its act after we exposed its fraudulent business model," Pershing Square said on the webpage.

"The former Herbalife distributors we spoke with-all of whom recently pursued the Herbalife business opportunity in their communities throughout the US-tell a different story. Each of these distributors, who are among the 2 million others who drop out of HLF every year, left the business after realizing that what they had been promised was a lie."

We're watching the webcast live. Be sure to check back for updates.

Shares of Herbalife were last trading down -$0.11, or -0.25%, at $43.32.

Ackman's big short

For more than three years, Ackman has been crusading against Herbalife, a multi-level marketer that sells nutritional shakes and weight-loss products.

In late December 2012, Ackman publicly declared via a 342-slide presentation that he was short $1 billion worth of Herbalife. He believes the company is operating as a "pyramid scheme" that targets poor people. It's his contention that regulators, specifically the Federal Trade Commission, will shut the company down.

Herbalife has always denied Ackman's allegations. We've reached out to the company for comment on today's webcast.

In March 2014, the FTC opened an investigation into the company. There hasn't been an update in that area.

It's believed that Ackman shorted Herbalife in the mid-$40s. In October 2013, he repositioned about 40% of his $1 billion equity short position for put options in an effort to reduce risk.

Ackman has said multiple times that he would take his Herbalife short "to the end of the earth."