Officers from the Criminal Assets Bureau were accompanied by divisional drugs squad detectives from Anglesea Street Garda Station and local officers from the financial investigations unit as they raided the houses on the northside of Cork City.

According to a senior Garda source, the raids took place at three different addresses at 8am.

Two of the houses raided were in Kerryhall Road, with the other in the Blarney Road area.

Three women and a man were arrested.

The women range in age from 21 to 52, and the man is understood to be 23.

Two of them were taken to Gurranabraher Garda Station for questioning, one was detained at Mayfield Garda Station and the other at the Bridewell Garda Station in the city centre.

The garda source said the operation was pre-planned and that the four people were targeted for suspected laundering of the proceeds of criminal activity, including drug trafficking.

He said the operation was linked to previous seizures of cash and drugs which had taken place in the region during the last eight to nine months.

They were being detained under section 2 of the Criminal Justice Drug Trafficking Act (1996), which includes a provision for money-laundering.

“This is a significant operation from a Cork perspective,” the senior garda source said.

He said the extended family were well known to the gardaí and would previously have been a target of garda investigations.

Last night, one of the women was released without charge.

The other three people remained in custody.