There is to be a full investigation into child sex abuse by Catholic clergy in the biggest diocese in the country, the Archdiocese of Dublin.

Circuit Court Judge Yvonne Murphy is to head up a statutory inquiry into how senior churchmen in Dublin - including Cardinal Desmond Connell - handled abuse allegations over more than three decades.

The inquiry is to select a sample of complaints or allegations between 1975 and 2004 to examine.

It is also proposed that the commission will investigate any instance of a diocese not implementing church guidelines in relation to child sex abuse.

The Government further announced that Minister of State at the Department of Health and Children, Brian Lenihan, is to begin an investigation into clerical sex abuse in all other dioceses in the State.

The Archbishop of Dublin, Dr Diarmuid Martin, has said the commission will have the full co-operation of the Dublin Diocese.