A representative for the Bureau of Prisons has confirmed that Ames passed away on Monday.

Ames, who spent 31 years with the CIA, confessed to receiving $3.8 million from Moscow in exchange for U.S. intelligence from 1985 up until his capture in 1994.

The information he divulged included the identities of ten Russian officials and one Eastern European who were secretly working for the United States or Great Britain. He also revealed details about spy satellite operations, eavesdropping tactics, and general espionage methods.

His actions are credited with leading to the executions of Western agents operating under the “Iron Curtain” and represented a significant blow to the CIA during the Cold War era.

Ames admitted his guilt to charges of espionage and tax evasion without a trial, resulting in a life sentence without the possibility of parole. Prosecutors highlighted that his actions deprived the U.S. of crucial intelligence for an extended period.

Expressing remorse, he acknowledged his “profound shame and guilt” for his “betrayal of trust,” which he admitted was motivated by a basic desire for money to settle debts.

But he downplayed the damage he caused, telling the court he did not believe he had “noticeably damaged” the United States or “noticeably aided” Moscow.

“These spy wars are a sideshow which have had no real impact on our significant security interests over the years,” he told the court, questioning the value that leaders of any country derived from vast networks of human spies around the globe.

In a jailhouse interview with The Washington Post the day before he was sentenced, Ames said he was motivated to spy by “financial troubles, immediate and continuing”.

Ames was working in the Soviet/Eastern European division at the CIA’s headquarters in Langley, Virginia, when he first approached the KGB, according to an FBI history of the case.

He continued passing secrets to the Soviets while stationed in Rome for the CIA and after returning to Washington.

Meanwhile, the US intelligence community was frantically trying to figure out why so many agents were getting discovered by Moscow.

Ames’s wife, Rosario, pleaded guilty to lesser espionage charges of assisting his spying and was sentenced to 63 months in prison.