The U.S. Attorney’s Office for the Southern District of New York on Tuesday announced that Gregoire Tournant, a chief investment officer at Allianz Global Investors U.S., has been charged with conspiracy to commit securities fraud, investment adviser fraud and obstruction of justice in connection with billions of dollars in investor losses.

Tournant surrendered to authorities in Colorado on Tuesday morning, officials said. His attorneys, Levine Lee co-founder Seth Levine and Buckley partner Daniel R. Alonso, said he plans to mount a “vigorous” defense.