The U.S. Justice Department is investigating the Coast Guard’s $24 billion Deepwater modernization contract.

The investigation is looking into the flawed design of modified patrol boats. A spokeswoman for Integrated Coast Guard Systems, the Lockheed-Northrop joint venture that previously ran the contract, said the companies were notified in December of a probe.

The spokeswoman said that the companies were told to save documents related to the project, which involves upgrading electronics and enlarging the 110-foot patrol boats.

The Coast Guard had announced Tuesday that it was taking over management of the contract from ICGS because of design flaws, poor contract oversight and numerous cost overruns.

It is not yet known how much, if any, revenue the loss of the projects will cost the two contracting giants or if the contract will be terminated and put up for re-bid.

Shares in Northrop were up 17 cents to $79.95 in afternoon trading Thursday on the New York Stock Exchange.