News - Middle East: A US Navy engineer has pleaded guilty to attempting to sell some of America’s most closely-guarded secrets about nuclear submarines to an unidentified foreign country.

Nuclear engineer Jonathan Toebbe was arrested in October along with his wife Diana Toebbe on charges of conspiracy to communicate restricted data and two counts of communication of restricted data.

They had both initially pleaded not guilty. The FBI laid out a detailed account of how the couple communicated to a foreign power offering to provide it with top-secret nuclear reactor documents in exchange for cryptocurrency.

During a hearing in West Virginia federal court on Monday, a US Justice Department attorney unveiled that Toebbe had entered a plea agreement with prosecutors. Toebbe, 42, admitted to conspiring with his wife to disclose restricted data, a violation of the Atomic Energy Act that carries a maximum sentence of life in prison.

Under the plea agreement, however, Toebbe will likely receive a much shorter prison sentence of between 12 to 17 years.

Toebbe's 45-year-old wife, Diana, has pleaded not guilty to charges of trying to assist her husband to sell secret data and her criminal charges still stand.

 However, Toebbe admitted that his wife was part of the conspiracy to sell the secretes and served as a lookout when he deposited information at a location in West Virginia set up by undercover FBI agents.

Toebbe, who had a top-secret security clearance, communicated with an undercover FBI agent posing as a foreign official over the course of several months, the Justice Department said.

The engineer had concealed a digital memory card containing documents about submarine nuclear reactors in a peanut butter sandwich to a "dead drop" location.

His admission that his wife was at least partially involved in the conspiracy raised the possibility of Toebbe testifying against his wife, should her case move to trial.