Brian and Kieran Collopy, two gang leaders were arrested following a drugs raid yesterday.
It is being said that detectives were sourcing information on these two men for nearly a year before carrying out the raid.
Brian Collopy also handed over ownership of a house when he admitted it was bought using the proceeds of crime.
Both men were previously imprisoned for threatening to kill a former associate.
A member of security said “There were times Limerick was run by the criminals. But that’s changing. Most of them are locked up now”.
A spokesperson from the Gardai confirmed that two males; one 43 years old, the other 40 years old, were arrested and are being detained at Henry Street Garda station.