(WineSpectator) - In a surprising turn for a onetime rising star in the wine industry, Charles A. Banks walked into a San Antonio courthouse wearing handcuffs Friday after surrendering to authorities. Two days earlier, a federal grand jury had indicted the financial advisor and founder of Terroir Capital—which owns or manages more than a dozen wineries in California, New Zealand, South Africa and Burgundy—on two counts of wire fraud, each of which carries a maximum penalty of 20 years in federal prison. The case stems from allegations made by former NBA star Tim Duncan, a longtime Banks client, who now says he was duped out of millions of dollars in various investments Banks made on his behalf.

Banks first met Duncan in 1998, while he worked as a financial advisor for pro athletes at CSI Capital Management. Wine was a hobby, but in 2000 Banks invested in a new Santa Barbara winery called Jonata. In 2006, he and real-estate developer Stan Kroenke bought Napa Valley's Screaming Eagle.

After Banks left both of those wineries, he founded Terroir Capital, inviting a select group to invest in building a winery company from scratch. He has assembled a portfolio of wine brands that range from legendary Napa winery Mayacamas to Santa Barbara pioneer Qupé—producing a total of 500,000 cases annually—along with smaller stakes in hotels and restaurants.

After Banks left CSI, he offered Duncan a stake in several investments he was putting together, including a sports merchandising company called Gameday Entertainment, for which Banks serves as chairman, and two funds at Terroir.

But in a lawsuit filed last year, Duncan alleged that Banks cost him millions through questionable advising and suspect deals. He says Banks persuaded him to make a $7.5 million loan to Gameday in 2012, which would be repaid over five years at 12 percent interest. His lawsuit alleges that Gameday failed to make all the payments. Duncan also claims Banks collected a 20 percent fee that he never agreed to.

Duncan's suit also alleged, "Banks encouraged, promoted, hustled and advised Duncan to invest in several wineries and investment funds that he controls. Banks has used these wineries and funds to secure substantial income for himself, but they have yet to return much, if anything, to Duncan."

Banks told Wine Spectator when the suit was filed that Duncan agreed to certain minimum investment periods but then tried to cash out early. "I knew that Tim was unhappy because he wanted to get out of some of his investments after his divorce," he said. "But we've got some terrific investments and I'm not going to let Tim Duncan or anyone else bully me into changing the fund and possibly hurting other investors."