Number of controversies have rocked police service
The latest Garda corruption probe is one of a series to rock the force in recent years.
Last June, Garda Sergeant Jimell Henry was jailed for 18 months for relaying information from the Pulse system to a drugs gang in Sligo.
Judge Keenan Johnson said her behaviour was deplorable and put the lives of members of the public at risk.
In 2014 detectives in Sligo became concerned confidential information was being leaked to an organised crime group and was being used to target a rival gang.
An investigation discovered Henry was routinely accessing the Pulse system and disclosing information.
A court heard in one two-week period alone, she made 900 inquiries on Pulse.
Almost three-quarters of these related to Sligo, even though she was stationed in Dublin at the time.
She pleaded guilty to three charges of disclosing information obtained during the course of her duty, knowing that it was likely to have a harmful effect, and four counts of disclosing operational details without authority, in December 2014 and January 2015.
Meanwhile, the force has also been rocked by allegations a garda had a sexual relationship with a female drugs suspect and tipped her off about a search.
The allegations have been subject to an internal investigation and the garda at the centre of the claims was suspended.
The matter is set to feature at the Disclosures Tribunal, which is examining claims Garda Nick Keogh was harassed after blowing the whistle on his colleague's alleged behaviour.
The Dáil has heard Gda Keogh has also alleged people with no previous criminal records were coerced into procuring drugs and selling them to undercover gardaí to boost detection rates.
Collusion between gardaí and criminals is not a new phenomenon.
In the 1990s a rogue garda was convicted for taking bribes from members of the gang who murdered journalist Veronica Guerin.
Ex-garda John O'Neill was jailed for four years in 1998 for taking bribes, including from members of John Gilligan's gang.