A garda arrested twice in a major corruption inquiry was previously probed for dodgy dealings in which a colleague was sacked.
The Mid West officer, who was tasked with managing high-risk informants, came under scrutiny in 2010 and 2011.
It was alleged he and a colleague had an inappropriate relationship with a criminal who they gave drugs to in return for details.
Senior officers from Cork were drafted in to investigate the incident and called for one of the gardai to be axed.
He was sacked but following a High Court case he was reinstated and is back working as a detective in Munster. No action was taken against the officer who is currently under investigation.
A source said: “An informant in the Mid West made a complaint and had taped conversations with the detectives.
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“During these meetings alleged evidence of wrongdoing was discovered.
“The probe was carried out by a group of investigators who were drafted in from Cork city’s detective branch. One key area of that probe was examining the disappearance of drugs from an evidence lock-up in Roxboro Garda station.”
Sources added although there were no charges recommended the probe did result in a young garda being fired.
The other officer was not dealt with under discipline procedures and after a break from the job he later returned.
He was arrested on Thursday morning for the second time as the National Bureau of Criminal Investigation continued their probe into alleged corruption.
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He was also held along with a superintendent on suspicion of leaking details to the gang and and an inspector for an offence under drug laws.
The probe centres on alleged interactions by the gardai with a major crime group in Newcastlewest.
The officers were allegedly snared after they were detected on phone taps.
It followed an incident in which the crime gang were allegedly informed by gardai the CAB was set to raid a money laundering operation in a car dealership.
The officers were released without charge and a file is being prepared for
the DPP. They have also been suspended pending the outcome of the probe.
