The Boston Red Sox have reportedly admitted to Major League Baseball that they improperly used electronic devices to steal signs from their longtime rival New York Yankees.

The New York Times reported Tuesday the Red Sox used a high-tech watch to relay signs by the Yankees catchers during a series last month at Fenway Park.

The Times said the MLB probe started after Yankees general manager Brian Cashman filed a complaint with the commissioner’s office that included video.

The newspaper said the video showed a member of Boston’s training staff looking at his Apple Watch in the dugout and relaying a message to players.

Sign stealing is allowed, but electronic assistance is prohibited.

The Red Sox hold a narrow lead over the Yankees in the AL East race.