Walsh was a seminarian at the time of the offence, which is the earliest recorded case of child abuse by him. He went on to become known as the 'Singing Priest' for his role in a travelling all-priest group before he was defrocked after his abuse of young boys began to emerge.

Walsh (61), formerly of North Circular Road, Dublin, was convicted last December after a trial at Dublin Circuit Criminal Court of the indecent assault of a girl at St Luke's, Kilbarron Park, Kilmore, Dublin, on a unknown date between April 17, 1973, and September 9, 1976.

He had pleaded not guilty. The victim was aged between seven and 10 at the time when Walsh locked her into a room and sexually assaulted her.

After the assault he told her it was only a game, stating: "We were only having fun, don't tell anyone". Walsh is currently serving a 16-year sentence imposed on him in 2010 for the rape and abuse of three schoolboys.

Judge Catherine Murphy said the abuse had had "profound and damaging effects" on the victim, now aged 50. She imposed the maximum sentence of two years and suspended the final year on condition he keep the peace for that period.

The court heard that the offence took place in a parish hall run at the time by the Sisters of Charity nuns and where Walsh helped out with maintenance work.