Key Soros Herbalife architect out

The chief architect of Soros Fund Management's bullish bet on Herbalife has quietly departed.

Paul Sohn, a portfolio manager at billionaire George Soros' influential personal investing shop, left the firm late last year, according to people familiar with the situation.

Sohn did not immediately respond to a request for comment.

"Paul Sohn's departure is unrelated to any position the firm may have or has had in Herbalife," Michael Vachon, a spokesman for Soros said in an email to CNBC.

Sohn is known as the man who got Soros into its position on Herbalife, the controversial nutritional supplements company that Bill Ackman and his Pershing Square Capital Management have famously bet against as a "pyramid scheme." The company strongly denies the charge.

In 2013, the New York Post reported that Sohn was gunning for Ackman. "George Soros broke the Bank of England," Sohn reportedly said at an investment ideas dinner, "George Soros can break the back of Ackman."

Read MoreHerbalife stockspikes as Soros said to be betting big

Soros has been cutting its Herbalife stake as the stock has taken a beating.

Soros held 1.89 million shares of the stock as of Sept. 30, down from 2.85 million the previous quarter, according to public filings. Herbalife is now Soros' 56th largest holding. Shares fell more than 50 percent in 2014 and the stock has fallen again in 2015 on high buying and selling.

Also recently departed from Soros are portfolio manager Randy Yuen and analyst Nils Tristan, according to people familiar with the situation.

Both men did not immediately respond to a request for comment.

Soros' chief investment office is Scott Bessent. Soros, a former hedge fund manager, is worth an estimated $24 billion, according to Forbes.