* Inquiry follows discovery of large baby grave
* To focus on church homes that housed unwed mothers
* Many unwed mothers forced to give up babies til 1980s
* Once-dominant church still runs many schools, hospitals
By Conor Humphries
DUBLIN, June 10 (Reuters) - The Irish government has ordered a comprehensive investigation into the treatment of children at Catholic church homes for unmarried mothers, including accusations of forced adoptions and unusually high mortality rates among children housed there.
Dublin has come under increasing pressure to examine practices at the institutions used to house children born out of wedlock between the 1920s and 1960s following the discovery of an unmarked grave with the remains of hundreds of babies near Galway.
"It is not an exaggeration to say the treatment of the women and their babies was an abomination," Prime Minister Enda Kenny, a practicing Catholic, told parliament. "If this issue isn't handled properly, then Ireland's soul in many ways will lie like the babies of so many of these mothers in an unmarked grave."
The Oscar-nominated film Philomena, which dealt with forced adoption of a child from a mother at one of the homes, also helped bring the issue to international attention.
The Roman Catholic Church dominated Ireland until the 1980s when a series of sex abuse scandals began to undermine its authority, but it still runs many schools and hospitals.
Minister for Children Charlie Flanagan told journalists the government had decided to establish a commission of investigation with full statutory powers to investigate "mother-and-baby homes" throughout the country.
Terms of the inquiry have not yet been established, but he said he hoped it would deal with high mortality rates, burial practices, adoption procedures and testing of medicine on children at the homes, and would seek church records.
"I am delighted that (the church) have indicated their willingness to cooperate with the process...so we can establish once and for all the facts of what went on during what was a very dark period of Irish history," he told state broadcaster RTE.
Government records show that throughout the 1930s, 40s and 50s, the mortality rate for children born out of wedlock in Ireland was often more than five times that of children born to married parents.
Until the 1980s, many unwed Irish mothers were compelled to give up their babies to secret adoptions.
Support groups for the survivors of the homes welcomed the news. "Certainly on the face of it, it is looking good," said Susan Lohan, director of the Adoption Rights Alliance, which has been calling for a similar inquiry for decades.
"The timeliness and the scope are the most important things here. We mustn't allow it to be dragged out." (Reporting by Conor Humphries; Editing by Mark Heinrich)