The Criminal Assets Bureau (Cab) is preparing to go to the High Court to seize half a dozen homes from well-known Limerick criminals in its latest crackdown on underworld figures.

Cab has identified homes belonging to members of the Dundon gang, as well as the Keane and Collopy gangs, that officers will claim in court were purchased with the proceeds of crime.

The investigations are at an advanced stage and officers from Cab, working with local gardaí, have built up extensive cases against several well-known criminals.

"There are a number of houses we're looking at – in the region of half a dozen. They belong to the Dundons, the Keanes and the Collopys," said a source. "We will have to prove that they paid for these houses with the proceeds or crime and we are confident we can do that. We will set it all out in affidavits to the High Court. We are in no rush to do this, we want to ensure the cases we have against them are airtight and the investigations are progressing well."

Eighteen months ago, Cab began a serious crackdown on Limerick criminals, which intensified in the last six months. Social welfare payments to several criminals were cancelled last year. In May 2008, several individuals had their social-welfare payments and benefits from the Department of Social and Family Affairs stopped.

They were told at Limerick District Court that until they could provide investigating authorities with detailed and legitimate evidence as to how they acquired the means to purchase numerous properties at home and abroad, as well as top-of-the-range vehicles and hi-fi equipment, their benefits would be stopped.

It is understood that in the majority of cases, the individuals have not applied to have this decision reversed.

In June 2008, a crackdown by gardaí and other state agencies on families involved in crime in Limerick led to some central figures involved in criminality leaving the city and moving abroad.