The man responsible for what the military called the Navy's biggest betrayal is dead.

John Anthony Walker, the former Senior Warrant Officer from Norfolk who supplied the Soviets with damaging tactical and military data, died in federal prison on Thursday in Butner, North Carolina at age 77.

29 years ago, in 1985, Walker's career as a spy came to an end in Norfolk Federal Court after his ex-wife Barbara alerted authorities.

Following an investigation by the FBI, it quickly unraveled to include not only John Walker, but also his brother Arthur and his son Michael and the family quickly became known in the media as a family of spies.

During his time as a Soviet spy, Walker helped them decipher more than 1 million encrypted naval messages.

After Walker's arrest, Caspar Weinberger, President Ronald Reagan's Secretary of Defense, concluded that the Soviet Union made significant gains in naval warfare attributable to Walker's spying.

Reacting to the news of his death on Facebook, his daughter Cynthia Walker Ober posted: "Good bye Dad... Rest peacefully, you are in Gods hands now."