The Vatican demanded on Tuesday that the heads of the Knights of Malta, which is a worldwide Catholic chivalric and charity group, cooperate with an inquiry ordered by Pope Francis.

In the latest battle of wills between the leaders of two of the world's oldest institutions, a Vatican declaration also rejected what it said was an attempt by the Knights to discredit members of a papal commission of inquiry.

Both sides have been locked in a dispute since one of the top knights, Grand Chancellor Albrecht Freiherr von Boeselager, was sacked on Dec. 6 in the chivalric equivalent of a boardroom showdown, supposedly because he allowed the use of condoms.

The Knights' top official, Grand Master Matthew Festing denounced the papal commission as meddling in the order's sovereign affairs. Festing stated that the five-member papal commission was "clearly unfit to address the situation objectively".

The order has 120,000 members, it was formed in the 11th century to provide medical care and protection for pilgrims to the Holy Land. The order has the status of a sovereign entity. It maintains diplomatic relations with over 100 states and the European Union (EU), it also has permanent observer status at the United Nations.

Festing fired von Boeselager, accusing him of hiding the fact that he allowed the use of condoms. Von Boeselager declared his sacking was not legitimate and appealed to the pope. The Vatican declaration appeared to reject the order's claim of total sovereignty. It stated that after receiving the commission's report this month, the pope will take "the most fitting decision" not just for the order but for the whole Church. The Church does not allow the use of condoms as a method of birth control and states that abstinence and monogamy in marriage are the best way to stop AIDS.