Political wrangling over the powers of the National Crime Agency operating in Northern Ireland are said to have left the region wide open to smugglers.
Almost a tonne of raw leaf tobacco and 10,000 suspected illicit cigarettes were this week seized in raids by Customs officers.
The huge tobacco haul was discovered in a vehicle at a farm in south Armagh on Tuesday.
HM Revenue and Customs said it was worth an estimated £236,000 in lost duty and taxes.
In separate searches on the same day, 10,000 illegal cigarettes were recovered.
A number of private and business addresses in Co Down were inspected and a vehicle as well as the cigarettes removed.
They were worth an estimated £2,800 in lost duty and taxes.
No arrests have yet been made in relation to either operation.
Earlier this month five people from counties Tyrone and Down were arrested as part of an investigation into a suspected £110 million tobacco fraud.
A Policing Board member last night welcomed the finds but said they showed the region was attractive for international crime gangs due to restrictions on the powers of the NCA.
"We are now clearly seeing the out-workings of not having the NCA in operation over the past year-and-a-half," DUP MLA Jonathan Craig said.
"It's no accident these quantities of illegal substances are being smuggled across the border into Northern Ireland.
"These gangs know only too well that at present if the gang leaders are caught, some of their assets can't be taken off them.
"For the past 18 months we have been a soft touch for smugglers and criminal gangs."
The NCA is expected to be operational here by May and one of its first priorities will be to confiscate the properties, cars, jewellery, cash and bank accounts of crime bosses.
Mike Parkinson, assistant director of criminal investigation at HMRC, said the illegal trade in tobacco was funding gangs across the world.
"Tobacco fraud is a highly organised global crime which costs the United Kingdom £2bn a year in lost taxes," he said.
"The trade in illicit tobacco is unregulated and makes cheaper tobacco more readily available to the young and vulnerable."
Customs are urging anyone with information about smuggled tobacco products to contact them or police.
Investigations into both this week's seizures are ongoing.Factfile
Smokers have been warned of the serious health threats posed by illicit tobacco.
Recently a notorious black market cigarette brand known to contain asbestos was found to be on sale in Belfast.
The dangerous Jin Ling brand is one of a host of illegal tobacco products increasingly available in the city. Smuggling them here is said to have become the "crime of choice" for organised gangs, who can make huge profits from their sale.