The Boston Red Sox have been fined an undisclosed amount for "sending electronic communications from their video replay room to an athletic trainer in the dugout" for the purpose of stealing signals from the opposing catcher, commissioner Rob Manfred announced Friday.

The New York Yankees filed a complaint against the Red Sox last month, triggering an MLB investigation.

The investigation found "insufficient evidence," according to a statement released by Manfred's office, that the Yankees used their YES Network cameras to spy on the Red Sox, as Boston had alleged in a counterclaim.

Manfred noted in his ruling that "all 30 clubs have been notified that future violations of this type will be subject to more serious sanctions, including the possible loss of draft picks."