DANBURY, Conn. — David H. Brooks, the founder of America’s leading supplier of body armor to the U.S. military, died in prison while serving a 17-year sentence for running a massive stock fraud scheme. He was 61.

The U.S. Bureau of Prisons confirmed that Brooks died Thursday at the Federal Correctional Institution in Danbury, Connecticut. On Saturday, spokesman Justin Long said prison officials cannot release additional details.

Brooks’ lawyer told Newsday that his client became ill Thursday and was taken to a hospital. He said it was unclear what led to his death.

“It was sudden and unexpected,” said Richard Klugh, Brooks’ federal appeals attorney in Miami.

Brooks, the founder and former chief executive of DHB Industries, was convicted in 2010 of securities fraud, conspiracy and other charges for masterminding a $185 million stock swindle and using the proceeds to pay for personal luxuries. Prosecutors said he threw extravagant bar and bat mitzvahs for his children in which entertainers such as Tom Petty, Aerosmith and the Eagles performed. They said he also bought a diamond-encrusted belt buckle in the shape of an American flag for more than $100,000.