Jefferson County, West Virginia – A US Navy engineer and his wife have been arrested after accusations of attempting to sell the design of US nuclear submarines to a foreign power, including on an SD card concealed in a peanut butter sandwich.

The US Department of Justice (DOJ) said Jonathan and Diana Toebbe allegedly sold information about the design of nuclear-powered warships to someone they believed was a representative of a foreign power.

The person was actually an undercover FBI agent, a statement from the department said.

Jonathan Toebbe, Navy nuclear engineer, held an active national security clearance, giving him access to restricted data.

The complaint affidavit alleges that in April 2020, Jonathan Toebbe sent a package to a foreign government containing a sample of data and instructions for establishing a covert relationship to purchase more.

"The affidavit also alleges that, thereafter, Toebbe began corresponding via encrypted email with an individual whom he believed to be a representative of the foreign government. The individual was really an undercover FBI agent," the DOJ statement said.

In June 2021, the agent sent $10,000 in cryptocurrency as a "good faith" payment. Shortly afterwards, the Toebbes traveled to a location to exchange information.

"There, with Diana Toebbe acting as a lookout, Jonathan Toebbe placed an SD card concealed within half a peanut butter sandwich at a pre-arranged 'dead drop' location."

A review of the card revealed that it contained information related to submarine nuclear reactors. In August, Toebbe made another "dead drop" of an SD card, this time concealing the card in a chewing gum package.

The FBI arrested the pair in October after he placed another SD card at a pre-arranged "dead drop." They will appear in federal court on Tuesday.