The treatment of young children in homes run by the Sisters of Mercy in Derry is at this stage the centre of the child abuse inquiry currently being held in Banbridge.
This week it emerged that in some cases children who were in the care of the nuns at Fahan were transferred to homes in Derry.
The counsel to the Historical Institutional Abuse Inquiry Christine Smith QC also said in one case a child born in the Republic was sent to Derry and later moved to Australia under a migrant scheme.
Giving details of some of the allegations being made about Termonbacca in the Creggan area and the Nazareth House in Bishop Street in Derry, Ms. Smith told the Inquiry it was claimed that some children were made to eat their own vomit.
The Inquiry was also told those who wet their beds were forced to put soiled sheets on their heads by members of a harsh regime which was devoid of love.
Ms Smith said that young people at Sisters of Nazareth properties were known by their numbers rather than names and many allegedly subjected to humiliation, threats and physical abuse.