Cardinal Keith O'Brien has resigned as leader of the Roman Catholic Church of Scotland.

His resignation today follows reports in the Observer over the weekend of alleged inappropriate behaviour towards four priests.

The allegations, which go back more than 30 years, are contested by the cardinal. However, he offered an apology in a statement for anyone he may have offended during his years of ministry.

The cardinal's resignation has been accepted by the Vatican with immediate effect. An Apostolic Administrator will be appointed to govern the Archdiocese of Saint Andrews and Edinburgh until a successor has been found.

The statement from Cardinal O'Brien read: "I have valued the opportunity of serving the people of Scotland and overseas in various ways since becoming a priest.

"Looking back over my years of ministry: for any good I have been able to do, I thank God.

"For any failures, I apologise to all whom I have offended."

The cardinal confirmed that he will not participate in the conclave to appoint Pope Benedict XVI's successor. This means there is no British representation in the election of the next pope.

Cardinal O'Brien continued: "I do not wish media attention in Rome to be focussed on me – but rather on Pope Benedict XVI and on his successor.

"However, I will pray with them and for them that, enlightened by the Holy Spirit, they will make the correct choice for the future good of the Church.

"May God who has blessed me so often in my ministry continue to bless and help me in the years which remain for me on earth and may he shower his blessings on all the peoples of Scotland especially those I was privileged to serve in a special way in the Archdiocese of Saint Andrews and Edinburgh."