PORTLAND, Oregon (Reuters) - A high-ranking former CIA officer, already imprisoned as a Russian spy, was sentenced to an additional eight years behind bars on Tuesday for sending notes to his Russian handlers from prison.

Harold “Jim” Nicholson, 59, pleaded guilty on November 8 to conspiracy to act as an agent for a foreign government and conspiracy to commit international money laundering.

“Today, former CIA official Harold Nicholson is being held accountable for once again violating his oath to protect America’s national security,” David Kris, Assistant Attorney General for National Security, said in a written statement.

In 1997, a federal judge in Virginia sentenced Nicholson to 23 1/2 years in prison for conspiracy to commit espionage.

Prosecutors said in court documents that Nicholson, who is serving his time in Sheridan, Oregon, used his 26-year-old son, Nathaniel, to carry messages to Russian intelligence contacts between 2006 and 2008.

Nathaniel Nicholson received cash payments of about $47,000 from the Russian agents as payment for his father’s past spying activities, prosecutors said in the documents.

“On a personal level, it shows the damage a father can do as he manipulates a son into a world of dishonor,” Arthur Balizan, Special Agent in Charge of the Federal Bureau of Investigation in Oregon said in a written statement.

Nathaniel Nicholson was sentenced to five years probation after pleading guilty in August 2009 to his role in the case.

As part of the guilty plea agreement, the elder Nicholson also forfeited to the government any profits from his story that might be generated from a movie, television show, book or other money-making enterprise.