Rosell says Barca will cut all ties with the capital club if they "cross the limits of sportsmanship" again.
He declared: "Madrid made accusations and conspiracy claims without any ground. They've tried to win off the pitch what they couldn't win on it. We want to turn the page now, but if Madrid cross the limits of sportsmanship again, we won't hesitate to break all relations.
"The news conference that the Real Madrid coach gave after the Champions League semi-final first-leg at the Bernabeu shamed anyone who considers themselves an athlete.
"I can assure you that if someone, in the name of FC Barcelona, had made an accusation of this kind we would have acted with firmness, denying it immediately and taking those responsible to court."