Ackman, founder of Pershing Square Capital Management, made the presentation in a conference call Tuesday after a New York Times article on Sunday questioned his 2012 short call on the nutritional supplements company.
In response to the article, Pershing Square held a 2 p.m. EST conference call to relay its research into Herbalife's China operations.
But Herbalife shares had only slipped 1.2% to $65.39 by market close Tuesday, a blip compared to the 18.2% loss suffered over January as scrutiny over Herbalife's operations heated up.
During the presentation, Pershing Square railed that Herbalife had violated China's direct-selling and pyramid-sales restrictions, citing research from OTG Research, a firm it hired to investigate the claims.
According to OTG's findings, Herbalife breached the law by "paying multi-level royalties based on unlimited downline levels" and "incentivizing distributors to recruit a potentially infinite downline in order for distributors to reap sales-based 'consulting fees'."
In a Q&A following the presentation, Ackman noted, "There's no circumstance under which we are wrong on whether or not Herbalife is a pyramid scheme. There's investment risk with respect to Herbalife. There's no certainty the government will investigate the company."
"I believe if the FTC, or the SEC or state attorneys general investigated Herbalife and looked into the issues we've identified there's a certainty the company would be found in violation of U.S. law, Chinese law, other law and the government would work to shut the company down," Ackman continued.
Herbalife responded to Ackman's presentation in a statement released on Tuesday. "Herbalife remains confident in its business in China, which is built on customers enjoying and benefiting from our nutrition products each and every day," it said. "We will continue to invest in this important market and collaborate with the Chinese government to deliver high-quality nutrition to the Chinese consumer through lawful direct selling practices. The presentation reflects Mr. Ackman's continued failure to fundamentally understand Herbalife's business model."