The US Department of Justice announced on Sunday the arrest of a US couple in West Virginia for trying to sell information about nuclear warships to a foreign country.

On Saturday, the FBI arrested Jonathan Toby, a nuclear engineer in the US Navy, and his wife, Diana, both in their 40s, and charged with violating the Atomic Energy Act in a criminal complaint.

In a statement, the Department of Justice said that within about a year the couple sold information known to be restricted data relating to the design of nuclear-powered warships to someone they believed represented a foreign power, explaining that the recipient of the information was in fact an undercover FBI agent.

The complaint alleges that Jonathan Toby, who through his job had access to restricted data on nuclear-powered warships, collaborated with his wife to trade data on submarine nuclear reactors for about $100,000 in cryptocurrency.

The complaint adds that, in April 2020, Toby sent a package to a foreign government "containing a sample of restricted data and instructions for establishing a confidential relationship," according to the statement.

According to the complaint, the FBI intercepted the expulsion, and the undercover agent posed as a representative of the foreign government, in order to establish a bond with the couple.

The customer sent Jonathan Toby - who used the pseudonym "Alice" - an email, offering him a token of thanks for the information, but Toby responded cautiously, asking for a place for delivery without any direct meeting, and that payment be made using cryptocurrency.

In the following months, the couple transferred several memory sticks containing data to the customer, and in the first delivery, which took place without any direct meeting, the chip was wrapped and hidden in half a sandwich.

According to the customer in the complaint, in other deliveries the strips were placed in a pack of gum or a pack of wound dressings.

The couple were arrested Saturday after leaving a memory stick at an agreed delivery location.

The statement added that US Attorney Merrick Garland praised the agencies involved in "thwarting the plot" and "taking this first step in bringing the perpetrators to justice."

The couple is scheduled to appear in federal court in West Virginia on the 12th of this month.