A controversial British bishop who is a prominent Holocaust denier has been expelled from his order.

Bishop Richard Williamson, 72, was handed his walking papers by The Society of St Pius X (SSPX), itself a breakaway order of the Roman Catholic Church.

"Monsignor Richard Williamson, having distanced himself from the leadership and the government of the Saint Pius X Society over a period of several years and refusing to show respect and obedience deserved by his legitimate superiors, has been declared excluded," the Order said in a statement.

"This is a painful decision."

SSPX was established in 1970 as a traditionalist and more conservative alternative to the Church in the wake of the modern reforms enacted by the Second Vatican Council in the 1960s.

In 1988, against the wishes of then-Pope John Paul II, Williamson was consecrated in Switzerland as a bishop in SSPX by its founder, archbishop Marcel Lefebvre.

Pope John Paul II excommunicated Williamson, but that ruling was rescinded in January 2009 by Pope Benedict XVI.

However, Williamson has never repudiated his extreme anti-Semitism. Among other things, he once told Swedish television that the Nazi did not use gas chambers.

"I believe that the historical evidence is strongly against, is hugely against, six million Jews having been deliberately gassed in gas chambers as a deliberate policy of Adolf Hitler", he said.

"I think that 200,000 to 300,000 Jews perished in Nazi concentration camps, but none of them in gas chambers."

He also alleged that 1.3-million people who were deported to concentration camps in Treblinka, Majdanek, Belzec and Sobibor were in fact transported to the Soviet Union, and not killed outright.

His comments were condemned by German Jews, Catholics as well as by German Chancellor Angela Merkel.

Williamson was put on trial in Germany in 2010 for denying the Holocaust -- the case was eventually thrown out.

He also strictly opposes healing the rift between renegade orders and the Vatican.  Indeed, he bitterly criticized attempts by the SSPX to seek a rapprochement with the mainstream Church.

“Instead of attacking the (Vatican II)… treachery, the SSPX now wants the traitors to give it permission to tell the truth?," he asked.