WHO, WHAT, WHY?
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The late Pope John Paul II would whip himself, according to a nun who helped to look after him. So how common is this practice in the Catholic faith?
"We would hear the sound of the blows," says Sister Tobiana Sobodka, who was in the next room to Pope John Paul II at his summer residence in Castel Gandolfo, near Rome.
Christ was scourged before the Crucifixion, Christians believe
Her evidence was given to the Vatican body which is considering whether to declare the Pope - who died five years ago - a saint.
Flagellation is the beating or whipping of the skin, most often on the back, and often drawing blood, as a bodily penance to show remorse for sin.
It was a widespread practice in some parts of the Catholic ministry up to the 1960s but is uncommon today, says Professor Michael Walsh, a Catholic historian.
Flagellation is acted out for symbolic purposes during penitential processions during Lent's Holy Week in Mediterranean countries, he says, as a reminder that Jesus Christ was whipped before the Crucifixion.
But in some countries like the Philippines, this re-enactment of the suffering of Jesus Christ - called the Passion play - can take a more extreme form and can draw blood.
Self-flagellation is only practised by a very small minority of Catholics
It is an expression of remorse for sins
It is also part of the Passion play in Holy Week
For others self-flagellation is a more private expression of faith.
It is thought to have come to prominence in Western Europe in medieval times around 600 to 800 AD as an extreme version of bodily penance, says Professor Lewis Ayres, a Catholic theologian at Durham University.
Early Christians believed that the notion of bodily penance allowed control of the body and emotions in order to focus more fully on worshipping God.
The practice continued in what Mr Ayres calls "the more conservative Catholic orders" well into the 20th Century and is still probably practised by a "tiny minority" today.
Pope John Paul II could be made a saint in 2010
Opus Dei, a branch of the Catholic Church which has a reputation for secrecy and featured in the Dan Brown bestseller The Da Vinci Code, is one of those groups unusual in doing this today, according to Mr Walsh.
Andrew Soane of Opus Dei says that what it calls "corporal mortification" goes back to the early Christians but it fell out of favour in the 1950s.
"It may happen that this change is reversed as people reconnect with their bodies and take control via moderate fasting and some corporal mortification, finding it a very healthy practice, which can overcome such unhealthy developments as drug use, sexual addictions, eating disorders and other body-hating approaches."
The Opus Dei website says some members self-flagellate for about one or two minutes a week, using a woven cotton string that causes some discomfort but does not draw blood.
Tradition of suffering
The revelation that Pope John Paul II, who died in 2005, possibly engaged in flagellation does not necessarily surprise Catholic scholars.
"Pope John Paul II was a firm believer in the New Testament tradition of suffering, a consistent theological historical position that a good life is simply preparation for death and life everlasting to follow," according to Mr Ayres.
"Part of a good life is remorse and remorse can be shown through physical suffering."
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Mr Walsh says Pope John Paul II grew up in an era where bodily punishment was seen as pious, and the possibility he may have engaged in it will aid the campaign for his beatification.
The Vatican body which decides these matters, the Congregation for the Causes of Saints, would regard this as a sign of his religious commitment, says Mr Walsh.
Whether the practice is more widespread in Asia today than Europe is harder for scholars to agree a position on.
Mr Ayres thinks it may be simply that "different forms of Catholic expression and piety take on different forms across the world".
"Certain cultures preserve older customs in a cultural context - and flagellation is no longer part of the cultural context of the vast majority of Catholics in the West," he says.
As to why flagellation seems to have disappeared, Mr Walsh is in no doubt.
"Early Christians thought the body was evil and needed to be controlled. Quite simply, we now have a greater understanding that such practices are not healthy."