DUBLIN, Ireland (AFP) -- The head of the Roman Catholic Church in Ireland apologised "with all my heart" yesterday over his role in a child sex abuse controversy that has rocked the country.

Cardinal Sean Brady has faced calls to quit from victims' groups over his attendance at meetings in 1975 where children allegedly abused by one of Ireland's worst serial paedophiles were asked to take a vow of secrecy.

In his annual Saint Patrick's Day address, Brady said he would be "reflecting carefully" in the coming weeks on what had happened -- and asked worshippers to "pray for me".

"I want to say to anyone who has been hurt by any failure on my part that I apologise to you with all my heart," he said in the address in Armagh, Northern Ireland.

"I also apologise to all those who feel I have let them down. Looking back, I am ashamed that I have not always upheld the values that I profess and believe in."

Brady has previously said he would only resign if asked to by Pope Benedict XVI.

The Catholic church is facing allegations of links to paedophilia in countries like Germany and Brazil as well as in Ireland, while the pope has been criticised over his handling of the issue.

Brady has come under fire after it emerged that he attended meetings in 1975 where two alleged victims of Father Brendan Smyth signed an oath of secrecy.

The church was investigating sex abuse complaints against Smyth, whose activities led to the fall of prime minister Albert Reynolds' coalition government in 1994.

Smyth, who is believed to have abused hundreds of children over a 40-year period in Ireland, Northern Ireland, Scotland and the United States, was finally jailed in the 1990s and died in prison.

Martin McGuinness, Northern Ireland's deputy first minister, said Brady should "consider his position" over the row.

"I think it is a very grave situation for the Catholic church and I do believe that Cardinal Brady should consider his position," he told state broadcaster RTE from Washington, where he is spending Saint Patrick's Day.

"I would be very surprised, and I think many Catholics would be very surprised, if he wasn't doing that at the moment."

McGuinness, a Catholic whose party, Sinn Fein, is also heavily Catholic, added: "Catholics throughout the island of Ireland want to see real leadership at this time."

But Irish Prime Minister Brian Cowen said while it was "an important issue", the government should not get involved.

"It is not a question for the state to get involved in church matters nor for the church to be involved in state matters," he told RTE, also from Washington.

In his address, Brady also called for an end to the "drip, drip, drip revelations of failure" by the church on the issue.

"The integrity of our witness to the gospel challenges us to own up to and take responsibility for any mismanagement or cover-up of child abuse," he said.