It was part of an international investigation into the illegal supply of ‘skunk’ cannabis into Northern Ireland.
Police believe those behind the racket are from South Asia.
Those arrested include four men and two women with ages ranging between 26 years and 33 years old.
PSNI is the lead investigator in an operation involving colleagues from the Italian Carabiniere and the National Crime Agency.
In a major search operation on Tuesday 24th March, detectives believe they have arrested significant members of a crime gang who have been involved in money laundering and drugs trafficking activities.
Police carried out 10 searches in Belfast, Greenisland, Bangor, Newtownards and Ballywalter, made 6 arrests and seized ‘skunk’ cannabis with an estimated street value in the region of £800,000.
All six are currently being questioned at Bangor PSNI Station.
In the same operation, two arrests were made and three searches carried out in the Prato and Bologna areas of Italy.
A further six were arrested in Italy today as the investigation continued to develop
The officer leading the investigation, Detective Inspector Andy Dunlop from Organised Crime Branch, said: “We believe we have established the source of a major supply of herbal cannabis trafficked into Northern Ireland.
“This is a substantial multi-agency international investigation which has involved various investigative tactics and methods – resulting in these searches, seizures and arrests.”
“We have seized £800,000 of herbal cannabis but our enquiries lead us to believe that much more has already been sent from Italy to Northern Ireland. In recent months, officers in Organised Crime Branch and local Districts have seized £1.2 million worth of herbal cannabis as part of this operation.
“All illegal drugs are harmful but this ‘skunk’ variety can be particularly dangerous because it can significantly increase a user’s likelihood of experiencing a psychotic episode.
“In Northern Ireland, we have searched properties in Belfast, Greenisland, Bangor, Newtownards and Ballywalter. Those arrested are being questioned at Bangor police station on suspicion of the importation of cannabis and conspiracy to supply cannabis and money laundering.
“This is a developing investigation and we are maintaining close contact with our colleagues in the Italian Carabiniere and the National Crime Agency as well as a number of other law enforcement agencies in the UK and Ireland.
“Our objective is to ensure we identify and apprehend as many of those allegedly involved in this criminality and bring them before the courts, as well as seize drugs and as many criminal assets as possible. Our inquiries will continue for some time.”