Hamburg  - The superior of an ultra-conservative group which is being re-admitted to the Catholic Church said in an interview Tuesday that he has told one his bishops, Richard Williamson, to "correct" his denial of the Holocaust.

"He should study the historical facts quickly and correct his false statements. The sooner the better," said Bernard Fellay.

The interview was reported by the German news website Spiegel Online, which said it received written replies to questions posed by telephone. Fellay heads the Society of Saint Pius X, a group opposed to modern Catholic theology.

There has been outrage, especially in Germany, over Williamson's claim to a Swedish television interviewer that there had been no gas chambers at Nazi concentration camps and "only 200,000 to 300,000" Jews had died in the camps.

Bishop Fellay, 50, said he told Williamson as soon as he saw the interview "to correct this nonsense. It should not have needed a papal demand to do so."

Fellay said he had suspended Williamson as head of the SSPX seminary at La Reja, Argentina, on January 31.

"I have forbidden him to make further public statements without my permission," Fellay added.

Fellay, Williamson and two other SSPX bishops were re-admitted to the Catholic Church two weeks ago to end a 21-year schism with an estimated 600,000 fundamentalist Catholics who had refused to follow the pope.

SSPX, which is hostile to contemporary lifestyles, is active in Germany, where it is opposed by most official Catholic bishops.

The lay people's committee of the Catholic diocese of Paderborn called Tuesday for SSPX groups to be put under police surveillance to establish if they were a threat to democracy in Germany.

Several politicians in the Social Democratic and Greens parties endorsed the call. (dpa)