Pope Benedict XVI on Saturday put his stamp of authority on the body that will elect his successor as he appointed 22 new cardinals at a time of roiling tensions in the Vatican administration.

The 84-year-old pontiff presented the new 'princes of the Church' with scarlet-red birettas and gold rings while urging them to "renounce the worldly style of power and glory" in a solemn ceremony in Saint Peter's Basilica.

The new members of the College of Cardinals 'are asked to serve the Church with love and vigour, with the clarity and wisdom of teachers, with the energy and moral force of pastors (and) with the faith and courage of martyrs', the pope said.

The German pope did not refer directly to recent days of high-profile leaks and corruption allegations that have raised fears of a power struggle at the heart of the Roman Catholic Church.

Vatican spokesperson Father Federico Lombardi has denied the rumours, saying that the leaks were intended to 'sow confusion' and cast the Church 'in a bad light'.

Among the key appointments were those of New York Archbishop Timothy Dolan, Toronto Archbishop Thomas Collins, as well as the bishop of Hong Kong, John Tong Hon, and Archbishop George Alencherry from India.

Critics say the appointments show a strong bias towards Europe, as out of the 125 cardinals under age 80 -- "elector cardinals" eligible to elect the pope in a secret conclave -- 67 are from Europe.

Just 22 are from South America, 15 from North America, 11 from Africa and 10 from Asia and the Pacific.

Moreover, the induction of seven Italians in Benedict's fourth consistory brings to 30 the number of Italian elector cardinals -- almost a quarter of the total, far outweighing any other country.

The new cardinals include nine other Europeans as well as two Americans, one Canadian, a Brazilian, an Indian and a Hong Kong Chinese.

Some observers say the Vatican's increasingly powerful Secretary of State Tarcisio Bertone is behind the promotion of Italians up the Church hierarchy.

Brazilian Joao Braz de Aviz is the only new cardinal from Latin America, the region with the largest concentration of Catholics.

The vast majority of previous popes -- more than 200 -- have been from Italy.

The key question being asked by Vatican insiders is whether Benedict -- who turns 85 in April and is well respected for his academic work as a theologian -- is becoming too distant from the day-to-day management of the Church.

The issue is crucial as Bertone's ascendancy is seen as being one of the reasons behind the recent rash of revelations.

One of the reported rumours was that the pope is lining up Milan Archbishop Angelo Scola to be his successor. Another alleged that the Vatican's bank was failing to comply with money-laundering rules.

Eighteen of the 22 newcomers are under 80. Of the electors, 63 have been named by the German pope and the other 62 by his Polish predecessor John Paul II.

Many of the nominations were virtually automatic -- for example, the bishops of Utrecht, Florence, Berlin, Prague, Toronto and New York, and certain long-serving Vatican prelates, of whom 10 were named Saturday.

Following the consistory, the pope announced that he will create seven new saints including the first Native American, a 17th-century Mohawk girl named Kateri Tekakwitha, on October 21.