A septic tank was used to dump the bodies of almost 800 babies and children in Ireland near a home for unmarried mothers run by nuns, new research has shown, throwing more light on the Irish Catholic Church's troubled past.

Death records suggest 796 children, from newborns to eight-year-olds, were dumped in a septic tank near a Catholic-run home for unmarried mothers, turning it into in a mass grave. The deaths occurred during the 35 years the home operated from 1925 to 1961.

The government announced it was examining the "best means" to address the "deeply disturbing" revelations.

Historian Catherine Corless, who made the discovery, said her study of death records for St Mary's home in Tuam in County Galway suggests the former septic tank near the facility is a mass grave.

The septic tank, full to the brim with bones, was discovered in 1975 by locals when concrete slabs covering the tank broke up.

Until now, locals believed the bones mainly stemmed from the Great Irish famine of the 1840s when hundreds of thousands perished.

St Mary's, run by the Bon Secours Sisters, was one of several "mother and baby" homes in early 20th century Ireland.

Thousands of unmarried pregnant women - labelled "fallen women" at the time - were sent to the homes to have their babies.

The women were ostracised by the conservative Catholic society and were often forced to hand over their children for adoption.

Health issues and problems associated with the homes have long been documented. As far back as 1944, a government inspection report of the Tuam home described some of the children as "fragile, pot-bellied and emaciated".

The recently discovered death records for St Mary's show that 796 children died from malnutrition and infectious diseases, such as measles and TB.

Conservative Catholic teaching at the time denied children of unmarried parents baptism and therefore burial in consecrated land.

The home was knocked down many years ago to make way for new houses, but the area around the unmarked mass grave has been maintained by locals.

A fundraising committee has now been formed and it is hoped a memorial will be built with all the names and ages of the children displayed.

Archbishop of Tuam Michael Neary said he would meet leaders of the Bon Secours Sisters to assist with the memorial.

Minister for children and youth affairs Charlie Flanagan said "active consideration is being given to the best means of addressing the harrowing details".

"Many of the revelations are deeply disturbing and a shocking reminder of a darker past in Ireland when our children were not cherished as they should have been," he said.

Archbishop of Dublin Diarmuid Martin said if a public inquiry into the "mother and baby" homes in Ireland was not established then a social history project was necessary.

He also said he supports "excavating what may be unmarked graves" at these sites.

The development is yet another damning disclosure of a Catholic Church-run institution in Ireland following almost countless revelations of abuse and neglect at schools or institutions in recent decades.

AFP