An independent investigation is to begin into claims gangs were paid to stop attacking builders on sites in West Dublin.
The High Court has heard how construction firms working for Dublin City Council gave criminals up to €1500 a week so they could continue building social housing.
It's alleged the protection payments were handed over in 2016 and 2017, following a ongoing threats and intimidation.
The Housing Minister, Eoghan Murphy, will appoint a person to lead an independent investigation.
He described the issues raised as "very serious matters, and we are treating them as such in Government".
"I will get to the bottom of this matter as quickly as possible", he said.
The Tanaiste, Simon Coveney, says he wasn't made aware of the claims at the time.
He was Housing Minister at the time, and while he has admitted his Department knew of the allegations, he doesn't remember being told personally.