A major Dutch investor lost $60 million when a Carlyle Group fund collapsed in March 2008. Now, he is paying for others to sue the US private equity firm, a high-stakes gamble that could make him hundreds of millions of dollars.

Louis Reijtenbagh, a 70-year-old former family doctor who became one of the Netherlands' richest men by investing in art, distressed debt and other assets, has already put an estimated tens of millions of dollars behind the case, according to people familiar with the matter. Meanwhile, Carlyle is suing him in Delaware for providing the funding for the litigation.