A forensic examination of the entire Bessborough site could take months, according to a forensic archaeologist.

Aidan Harte was speaking at the oral hearing by An Bord Pleanála into a planning application for 179 apartments in the grounds of the former mother-and-baby home at Bessborough in Cork.

Mr Harte, who was responding to questions from the Senior Planning Inspector Karen Kenny, qualified his estimation on the length of time it would take by pointing out the exploratory nature of such an examination, "..so the progress can't gauged on what we know right now regarding the forensic level of the examination".

Mr Harte gave evidence yesterday suggesting ground-penetrating radar at specific locations on the site if the housing development project is approved.

This evening, Inspector Karen Kenny who is chairing the oral hearing sought further clarity from the forensic archaeologist.

She questioned the process of system-testing at a site where there's an unknown burial ground.

Mr Harte said it was a matter of starting on one end of the site and continuing to the other side.

"If and when" human remains are encountered the work stops pending involvement of the coroner, he explained.

The forensic archaeologist said there were multiple techniques that could be used to forensically assess a site, the goal being, not to disturb remains but establish their presence.

"Oversight is critical", he said. "It's not in pre-existing legal framework at the moment, but that oversight would be critical."

Inspector Kenny asked Mr Harte whether it was common or uncommon for a report by a forensic archaeologist to be inconclusive.

Mr Harte said it was rarely inconclusive.

The hearing, which was due to conclude this evening, will continue tomorrow.

Ms Kenny suggested that attendees think about tomorrow's hearing overnight, based on the final evidence regarding archaeological excavation.

Mr David Holland SC who is representing the developer WMB Two Ltd, said they weren't resistant to Mr Harte's evidence and would "do whatever needs to be done".

He said he viewed Mr Harte's evidence as primarily giving confidence and guidance to council in agreeing details of archaeological excavation.

"If the board wants to go into that detail regarding an archaeological excavation we've no objection to that," he said.

Developer MWB Two Ltd has applied to An Bord Pleanála under the Strategic Housing Initiative for permission to build 179 apartments in three blocks on a 3.7 acre site in the grounds of Bessborough.

Meanwhile, an expert in ordnance survey mapping told the oral hearing that he believes an area marked as a 'children's burial ground' on a 1950s ordinance survey map is correct.

John Clarkin, who has worked for Ordinance Survey Ireland for over 40 years, was brought before the oral hearing by David Dodd BL - who is representing the Cork Survivors and Supporters Alliance.

Developer MWB Two Ltd has applied to An Bord Pleanála under the Strategic Housing Initiative for permission to build 179 apartments on a 3.7 acre site on the grounds of Bessborough.

Mr Dodd put it to John Clarkin that the developer claims the children's burial ground is in the nuns cemetery, where congregation of the Sacred Hearts of Jesus and Mary nuns were buried on the grounds.

However, Mr Clarkin noted the scale font stating 'children's burial ground' on the 1950s map - which is located outside of the nuns' cemetery.

He said he believed the children's burial ground is where the final reviser put it on the map.

Mr Clarkin said it was his belief that a tick and a circle around the words 'children's burial ground' showed that the final map reviser confirmed this in the 1950s.

"What I'm saying is that is the position and wording correct - it's more than a burial ground, it's a children's burial ground", he said.

He reiterated his view that 'children's burial ground' was too important a word not to write it in the area of the burial ground.

David Holland SC suggested that the font size of words had nothing to do with the size of the feature, but the importance of the feature.

Mr Clarkin disagreed.

"My own view is that the size of the text is saying, it's in that field and it's not just a small area but it's a big area", he said.

Earlier in the hearing, Mr Dodd pointed out that the Fifth Interim Report by the Commission of Investigation into Mother and Baby Homes diminished the argument that children and mothers were buried with nuns.

He suggested that nuns and children being buried together at a mother-and-baby home would have been unprecedented and he pointed out it had not happened at any other home.

One of the survivors of the home, Terry Harrison, addressed the hearing. She said that as a "living witness" she had huge concerns listening to experts at the oral hearing yesterday and this morning.

"I firmly believe that there are children and young girls buried in the grounds of Bessborough", she said.

Ms Harrison said part of history will be erased again.

She said the Bessborough institution and the area surrounding it needed to be separate from all development to allow future generations to "come to see the place where we were denied our human rights and tortured in some places".

Two Cork county councillors also made submissions to the hearing.

Lorna Bogue and Dan Boyle of the Green Party expressed their concerns about development at the site.

Cllr Boyle, who has a family connection to the former Bessborough home, said more certainty was required from the developer.

Today's hearing is taking place under strategic housing legislation which has a sunset clause.

Cllr Boyle described it as "controversial and discredited legislation".

He questioned the morality of an application under legislation which will not exist in a couple of months.

In his submission to the hearing, Sinn Féin Cork South Central TD Donnchadh Ó Laoghaire noted the sensitivity around the discussion about children's burial grounds.

While he acknowledged the need for housing and apartments in Cork, he said the issue went far beyond housing.

Mr Ó Laoghaire described the national mapping survey evidence heard this morning as "compelling".

He said the evidence by Mr Clarkin made it hard to accept that the children's burial ground "could coincide" with the nun's burial ground.

The Commission of Investigation into Mother and Baby Homes found that 923 babies were born at or associated with Bessborough died between 1922 and 1988.

Mr Dodd said the views expressed by survivors is that they want somewhere to go to remember their children and siblings - to sit on a bench, lay a flower and have a moment.

He said that while the Cork Survivors and Supporters Alliance is not against development on the site - the difficulty they face is that the developers want to place the apartments on the children's burial ground.

Mr Dodd said on clear balance of probability the Alliance agrees the children's burial ground as recorded on the tracing drawing.