American cardinals have given several briefings in Rome to discuss the challenges facing the Roman Catholic Church.
The Americans have called for the reform of the Roman Curia, the governing body of the church, which has a reputation as a hotbed of corruption.
But the briefings were stopped and the Americans gagged after other cardinals expressed fears of negative publicity relating to the conclave, the secretive election by which a new Pontiff will be chosen.
The American cardinals said concern had been expressed "about leaks of confidential proceedings reported in Italian newspapers".
The Vatican denied ordering the cardinals to cancel the briefings.