Frank Smith, 70, a central figure in the bloody Attica prison uprising who later became a spokesman for fellow prisoners in a lawsuit against New York state, died July 31 at a hospital in Kinston, N.C. He had cancer.

Mr. Smith was appointed by fellow inmates to keep prisoners under control amid negotiations after 40 prison employees were taken hostage during a four-day standoff at Attica that began on Sept. 9, 1971.

The uprising involving nearly 1,300 inmates erupted after several months of complaints about conditions at the prison. It ended in the deaths of 32 inmates and 11 prison employees, most of whom died after New York Gov. Nelson Rockefeller ordered state troopers to storm the prison and retake control.

After the guards took over, Mr. Smith, who was serving time for armed robbery, was tortured after being falsely accused of castrating a guard. According to court testimony, Mr. Smith was forced to lie naked on a table and was burned with lighted cigarettes and hot shell casings. He later testified that he was ordered to hold a football under his chin and was threatened with castration and death if the ball were to drop.

Mr. Smith was released from prison in 1973. He was indicted for his role in the riot but was later granted amnesty by Gov. Hugh Carey and eventually received $375,000 as part of a settlement.

Mr. Smith acted as a spokesman for Attica inmates in the federal civil rights lawsuit against prison and state officials over the treatment of prisoners by law enforcement officials during the uprising. It ended in 2000 with a $12 million settlement.

Mr. Smith, a strapping man with a baritone voice, served as the ad-hoc chief of security during the four-day uprising. Survivors include his wife.