The Government has approved an extension for the Commission into Mother and Baby Homes.
The commission will take another year to report, despite already being a year past deadline.
It sought an extension and had been due to give results next month.
Now the Government has approved a further 12 month extension - with the volume of work being larger than expected.
Children's Minister Katherine Zappone has said she knows it is not the news the survivors and their families want to hear, but the extension will allow the commission to comprehensively report.
It has so far heard from 519 witnesses.
A general view of the site of a mass grave for children who died in the Tuam Mother and Baby home in Co Galway | Image: Niall Carson/PA Archive/PA Images
An interim report delivered to ministers on Tuesday has said there are significant challenges investigating burial practices at the various sites.
It said a report into the burial of people who died in the homes is now due in March.
The commission advised the minister that it plans to conduct geophysical surveys on the burial grounds at the former Sean Ross Abbey institution in Co Tipperary.
Minister Zappone also said the delay in the final report from the commission will not affect planned excavations at the Tuam site in Co Galway, which are due to begin later this year.
She has previously pledged that "families will get the answers they are seeking" from investigations into mother and baby homes.
In 2017, the commission confirmed 'significant quantities' of human remains were found at a site in Tuam.
