A Bus Eireann driver was arrested after failing a roadside breath test as passengers sat in the vehicle.
The man, in his 50s, was detained on suspicion of drink-driving after being stopped in Cork city on New Year's Day.
Gardai made the arrest while on patrol on Western Road on Wednesday.
The driver was taken to Bridewell Garda Station after the intoxication test.
However, gardai confirmed he has since been released and that a file will be prepared for the DPP.
A garda spokesman told the Irish Mirror: "Gardaí on patrol on the Western Road in Cork City stopped a bus and conducted a roadside breath test on the driver which returned with a fail.
"A male in his early 50s was arrested at the scene on suspicion of drink-driving and brought to Bridewell Garda Station.
"He was later released without charge. A file will be prepared for the Director of Public Prosecutions."
Bus Eireann confirmed to the Irish Mirror that one of its drivers on the 220 route from from Carrigaline to Ballincollig was taken into custody.
And a spokesman added that the company would like to apologise to any customers impacted by the incident.
He said: "Bus Éireann can confirm that the driver of the 1148 Route 220 service from Carrigaline to Ballincollig was detained following a roadside check at Victoria Cross on the 01st January 2020.
"The vehicle was in service at the time, all passengers were transferred onto another vehicle with a minimal delay.
"We would like to apologise to any customers impacted."
