A man in his 40s arrested as part of the investigation into the Creeslough explosion has been released without charge.
Gardaí said a file will be prepared for the Director of Public Prosecutions.
He was the sixth person arrested in the investigation into the incident.
Ten people lost their lives following an explosion at a service station in the Co Donegal village in October 2022.
Gardaí said the investigation continues to be led by local gardaí in the Donegal Division.
The investigation is supported by the Garda National Bureau of Criminal Investigation and other agencies including the Health and Safety Authority and the Commission for the Regulation of Utilities.
