Senior Catholics are said to have been "mystified and astonished" when they heard that the purveyor of newspaper sex, scandal and nudity was made a Knight Commander of St Gregory at a ceremony in Los Angeles last month.
News of the award was kept out of Mr Murdoch's British titles - the Sun, the Times, the Sunday Times and the News of the World - at his request, although it is provoking outrage in the religious media and in Ireland, where many Catholics have reacted with anger that Mr Murdoch, who is not a Catholic, appears to have been honoured purely for donating large sums of money to the church. He and his wife, Anna, who is a Catholic, are known in Los Angeles as large contributors to the Archdiocesan Education Foundation, although specific amounts are not known.
The award was made by the Pope at the suggestion of Cardinal Archbishop Roger Mahony of Los Angeles. His recommendation was vetted by the Secretariat of State at the Vatican before being given the approval of the pontiff.
The knighthood is bestowed upon people of "unblemished character". It was presented by the Cardinal at St Francis De Sales Church in Los Angeles on 11 January. Other recipients included Bob Hope and Roy Disney, of the Walt Disney empire.
The reaction of Catholics in Britain has been almost unanimously negative.
Deborah Jones, editor of the Catholic Herald, said: "We have been receiving a much larger mailbag that usual, about 99 per cent of it asking: `What the hell is the church doing giving him a knighthood?'
"The great majority are complaining about page 3 girls and soft pornography in his newspapers and on his satellite channels. Some of the more thoughtful ones are expressing concern over his monopolistic tendencies and his [legal] reluctance to pay taxes. Worst of all, it does the church no good at all because it gives the impression that these honours can be bought."
Joanna Bogle, of the Association of Catholic Women, described the decision to honour Mr Murdoch as "absurd".
Speaking in a personal capacity, she said: "It sends out the message that you can make a living out of something - soft pornography - that is regarded by the Church as sinful, and yet you can be awarded for it. The Knighthood of St Gregory is supposed to be about honour and chivalry and and splendour. To give it to Murdoch is ridiculous and wrong."
Fr Kieran Conry, director of the Catholic Media Office, confirmed that some Catholics had been complaining. "Some have said that this man is a purveyor of pornography and filth. The News of the World may not be everyone's idea of a good read, but in general, no one could say Mr Murdoch has done anything evil."
Ann Widdecombe, the Tory MP who converted to the Catholic church, said she was "astonished" at the award. But she added: "I hope that now ... he might feel obliged to make some of his newspapers conform to Catholic teachings. It is never too late for a sinner to repent."
News International said Mr Murdoch did not wish to comment.