According to News of the World, los Merengues are demanding £17million from Ronaldo after he recently announced that he would not be moving to the La Liga giants this summer.
The Portuguese superstar seemed a certainty to leave Old Trafford after ignoring Sir Alex Ferguson's messages while at EURO 2008 and reiterating his life-long desire to ply his trade at the Santiago Bernabeu.
But the United boss has repeatedly insisted that his prize attacker will be going nowhere, and that indeed seems to be the case after the two met for crunch talks earlier in the week.
However, the matter is not done and dusted just yet, as Madrid are now claiming that the 23-year-old agreed terms with them and had a clause inserted in his contract that entitled the Spanish champions to a hefty sum of compensation.
The continental press reports that Real president Ramon Calderon will only forego the fee if an agreement is struck that will see Ronaldo head to los Blancos next summer.
Such an outcome remains highly unlikely, however, given relations between the two clubs have disintegrated throughout the saga.