A Navy nuclear engineer pleaded guilty Monday to trying to sell submarine secrets to FBI agents whom he thought were working for a foreign country. 

Jonathan Toebbe, 43, who as part of his job had a top-secret security clearance, pleaded guilty in federal court in Martinsburg, West Virginia, to a single count of conspiracy to communicate restricted data. 

The sentencing, agreed to by lawyers, calls for a potential punishment between roughly 12 years and 17 years in prison.

Toebbe and his wife, Diana, were arrested last October after prosecutors said he had repeatedly sold submarine secrets to someone he thought was a foreign government representative but was actually an undercover FBI agent. 

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During the plea hearing, Toebbe admitted that he conspired to pass classified information to a foreign government, causing "injury to the United States."

As part of the plea deal, Toebbe agreed to help federal officials with locating all classified information in his possession, as well as the roughly $100,000 in cryptocurrency that was paid to him.

Diane and Jonathan and Toebbe  ( )

Court documents have not disclosed which country Jonathan Toebbe was looking to sell the information, nor was it disclosed in court during the plea hearing Monday. 

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Prosecutors allege that Jonathan Toebbe also told his contact person that he might need to leave the country on short notice. 

Toebbe’s wife was accused of serving as a lookout at several prearranged "dead-drop" locations at which her husband deposited memory cards containing government secrets, concealing them in objects such as a chewing gum wrapper, a Band-Aid wrapper and a peanut butter sandwich. She has pleaded not guilty and the case against her remains pending.

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FBI agents who searched the couple's home in Annapolis, Maryland, found a trash bag of shredded documents, thousands of dollars in cash, valid children's passports and a "go-bag" containing a USB flash drive and latex gloves.

The Associated Press contributed to this report