Nearly a quarter of the babies born to Irish mothers and exported to the US for adoption were born at the Sean Ross Abbey, Co Tipperary, the convent at the centre of the film Philomena.

Two seven-year-old girls have handed ministers a petition signed by 30,000 people demanding a judge lead the inquiry into church-run, state-sanctioned institutions for single mothers.

The religious order behind three of Ireland’s largest and most notorious mother-and-baby homes is unable to confirm how many children were buried on the sites or if they were all buried in coffins.

A campaign aimed at shaming the Irish State into opening an estimated 60,000 adoption files is gathering pace on the back of Oscar-nominated film Philomena.

The real-life inspiration behind the film Philomena told a star-studded audience in Hollywood that mothers in Ireland forced to give up their children for adoption have “yet to receive the justice they deserve”.

There are lots of Philomena Lees in Ireland, writes Conall Ó Fátharta