The couple suspected of abandoning a baby boy in a cathedral in the Republic of Ireland on Friday are in police custody in Wales.
It is understood that the man (25) and woman (22), who are alleged to have taken the eight-month-old boy from his legal guardian in Nottinghamshire on Thursday, handed themselves into a police station in Wales.
Gardai have confirmed that they are no longer seeking the couple who were seen in the vicinity of the Cathedral of the Assumption in Carlow on Friday, shortly before the baby was found unattended in a buggy in a side-porch of the building.
They were reported to have been crying as they left the cathedral. Gardai later issued an alert regarding their whereabouts as concerns mounted.
But it is understood the couple took a ferry to Wales on Saturday morning, and are now being dealt with by British police.
A police spokesman said: "Nottinghamshire Police are investigating the circumstances which led to an eight-month-old boy being taken from his home to the Irish Republic.
"Police have worked extensively to locate the child and had already established that he may have been taken to Ireland when the Irish police confirmed at about 3.30pm on Friday that he had been found safe and well near a cathedral in the town of Carlow.
"The child had been left with a note giving his name and date of birth."
Police said the boy would be reunited with his legal guardian this week.
Officers added that they were "concerned" about a man and a woman believed to have been involved in the incident.
"We can confirm that a man and a woman have been detained in connection with this incident and are in custody."
Meanwhile, the baby remains in the care of the Health Service Executive (HSE), which will liaise with their counterparts in England in the coming days with a view to reuniting the child with his legal guardian.
"The baby is fine, he's happy and he is safe," a garda spokesman said.
It is understood the HSE may seek a formal court order today to keep the baby in care here until details regarding his return to England are finalised.
Gardai handed him over to social workers on Friday afternoon and he has been in emergency care since then.
The HSE said that, under the terms of the Childcare Act, it could not comment on such cases and could not say anything that might lead to a child's identity being revealed.
Nottinghamshire police confirmed that a baby went missing from his home in Kirkby-in-Ashfield on Thursday. His name and date of birth was written on a note attached to his buggy when he was found at 2.20pm on Friday by a woman visiting the cathedral in Carlow.
Gardai said that the couple had "no obvious connection" with Carlow and it is thought they may have travelled in a rush to Ireland by ferry on Friday morning, before deciding to abandon the boy in the town as they drove through the country.
They were travelling in a white Renault Clio, which was captured on CCTV footage close to the cathedral.