Bernie Parrish, a two-time Pro Bowl defensive back who championed players' rights in the 1960s in battling the NFL over fair treatment, has died at age 83.

According to the New York Times, his nephew Marc Parrish said the cause of death was metastatic prostate cancer. Parrish reportedly passed away Wednesday at his Springfield, Mo., home.

Originally a ninth-round pick in the 1958 NFL Draft out of Florida by the Cleveland Browns, Parrish developed into a solid starter in the team's secondary by his second season, when he notched five interceptions.

In 1960, Parrish earned the first of his two Pro Bowl selections when he picked off six passes for an NFL-high 238 interception return yards and a touchdown. He snagged a career-best seven interceptions the following season in 1961.

Parrish played eight seasons with the Browns (1959-1966), picking off 29 passes in Cleveland, which ranks seventh in franchise history. He was a starting defensive back on the Browns' 1964 NFL championship squad that blanked the Baltimore Colts 27-0 in the title game.

Parrish fought for players' rights as a vice president with the NFL Players Association, and campaigned for the firing of then league commissioner Pete Rozelle -- which at the time almost resulted in his being traded away by Browns owner Art Modell.

"I'll stick to my guns and fight for a new commissioner," Parrish said then. "Paul Brown (his former Browns head coach) is the answer to our problem."

The Browns finally cut Parrish in 1966, and he later signed a contract with the AFL's Houston Oilers, where he finished his playing career.

After retirement, Parrish tried to forge a partnership in a joint players union combining NFL and AFL players. He later penned a best-selling book "They Call It A Game," where he criticized the "con men who sell the National Football League like cosmetics" for allegedly taking advantage of the league's players.

--Field Level Media