Scotland’s Roman Catholic archbishop is contesting accusations of “inappropriate behavior” with priests, claims leveled as Cardinal Keith O’Brien prepares to join the conclave that will choose a new pope.

British newspaper The Observer reported Sunday that three priests and one former priest have leveled allegations against O’Brien that date back 30 years. The Observer did not recount details of the claims or identify any of O’Brien’s accusers, but said one of the priests alleged “that the cardinal developed an inappropriate relationship with him.”

O’Brien did not attend Mass at St. Mary’s Cathedral in Edinburgh on Sunday, but the Scottish Catholic Media Office told CNN that the cardinal “contests these claims and is taking legal advice.”

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His accusers took their complaints to the Vatican representative in Britain and demanded O’Brien’s resignation, The Observer reported. At the Vatican, Father Federico Lombardi, a spokesman for the church, told reporters that Pope Benedict XVI has been informed of the allegations.

More: Scotland’s Archbishop Contests ‘Inappropriate Behavior’ Claim