The News of the World says United chief executive David Gill has written to the Premier League over accusations their rivals tapped up Heinze, now of Real Madrid, this summer. League chiefs will discuss the case this week which could lead to a formal complaint from Old Trafford and leave Liverpool facing a Premier League charge.
And in a separate probe, the League will investigate claims Crystal Palace were asked to sign Heinze from United before selling him on to Liverpool.
If they are satisfied that happened, the case will be handed to the FA for them to take disciplinary action.
That could land Liverpool with two huge fines and add more fuel to the simmering feud between Sir Alex Ferguson and Rafael Benitez