The suspects, aged between 33 and 43, were all held on suspicion of conspiring to supply class A drugs on Tuesday during raids in the Carrickfergus area.
It is part of a long-running investigation into alleged organised crime activities by paramilitary group the South East Antrim UDA.
The group is a breakaway faction of the UDA and is suspected of being heavily involved in criminality including several murders in recent years.
NCA deputy director of investigations Craig Naylor said: “This operation is hugely significant, and we believe it will have substantially disrupted the drug dealing activities of the South East Antrim UDA.
“The investigation will continue with the evidence we have retrieved.
“The SEA UDA have long been known to be involved in many forms of organised criminality, doing untold damage to the community and exerting fear in neighbourhoods.
“Working with our partners in the PCTF we are determined to do all we can to bring that to an end.”
The arrests related to the discovery of more than one kilogram of cocaine that was found during searches of two cars and land in the Greenisland area of County Antrim in November 2020.
Police Service of Northern Ireland’s head of criminal investigations branch, Detective Chief Superintendent John McVea, said: “Working with our partners in the paramilitary crime task force, we are committed to continuing to target the organised criminality associated with all paramilitary gangs who exploit their local communities to cause harm and create fear.
“Today’s search and arrest operation is a significant milestone in an investigation into the drug dealing activities of the South East Antrim UDA.
“The harm caused by illegal drugs to individuals and communities is evident.
“Drugs cause nothing but destruction and distress, not only to the people who take them, but also to their families who deal with the heartbreaking fallout associated with drugs, including death, spiralling debts and intimidation.
“Criminals who supply illegal drugs don’t care who they harm in the process of making money to line their own pockets and fund other paramilitary activities.”