Bishop Richard Williamson, centre, is escorted out of London's Heathrow airport by police and security officers after his arrival from Argentina. (Kirsty Wigglesworth/Associated Press)

A British bishop who ignited an international controversy because of his denial of the scale of the Holocaust arrived in London Wednesday after Argentina threw him out.

Flanked by police and security guards as he emerged from Heathrow Airport, Bishop Richard Williamson refused to speak to reporters and was hustled into a waiting car.

Williamson, 68, belongs to the Society of St. Pius X, an ultraconservative religious order that has been estranged from the Roman Catholic Church for decades. He had been living at a seminary 40 kilometres west of Buenos Aires since 2003.

Last Thursday, the Argentine government gave Williamson 10 days to leave the country for failing to declare a job change as required by immigration law, as well as having "deeply shocked Argentine society, the Jewish people and all of humanity," with his controversial views on the Holocaust.

Williamson had expressed some of those views in a Swedish television interview broadcast on Jan. 21. He denied the existence of Nazi gas chambers during the Second World War, and said only 200,000 to 300,000 Jews were killed, not six million.

The statements deeply embarrassed the Vatican at a time when it has been trying to improve relations with Jews.

The Vatican had recently lifted the excommunication of Williamson for being ordained without the Vatican's permission by the founder of the Society of St. Pius X.

Pope Benedict XVI has been working to reunite the Roman Catholic Church with the group. However, the Vatican has demanded that Williamson recant his views on the Holocaust before he is fully readmitted to the church.

Earlier in February, the bishop promised to review historical evidence concerning the Holocaust before deciding whether to recant.

Williamson also questioned the Holocaust while serving as rector of the St. Thomas Aquinas Seminary in Winona, Minn., between 1988 and 2003.

According to the Anti-Defamation League, Williamson declared in a 1989 speech that "Jews made up the Holocaust, Protestants get their orders from the devil and the Vatican has sold its soul to liberalism."