A man questioned in connection with the disappearance of Mary Boyle has been released from garda custody without charge.
The 64-year-old, who was detained at Mullingar Garda Station on suspicion of kidnapping the child, was arrested on Tuesday.
The man had been detained at Mullingar Garda Station under Section 4 of the Criminal Justice Act 1984.
A file is to be sent to the Director of Public Prosecutions pending further investigation.
Mary went missing from her grandparents’ home at Cashelard in Donegal on 18 March 1977 and has not been seen since.
Gardaí have also renewed their appeal for information.
Gardaí say the investigation into the disappearance of Mary Boyle is ongoing. Gardaí continue to liaise with Mary’s mother, Ann Boyle.