Officers mounted the operation after receiving information the drugs, from China, were being brought into Dublin Airport and then on to Letterkenny.
One man appeared at Letterkenny Circuit Court charged with the possession, sale, and supply of almost €210,000 worth of the mephadrone drugs.
Simon Crawford, aged 29, of York Avenue, Portstewart, Co Derry, later admitted he had helped organise 10 to 15 such deliveries.
Gardaí and customs officers monitored the drugs as they came from Frankfurt Airport and then arranged a “controlled delivery”. They called to the drop-off address at 29 Glentane Close on Nov 6, 2012, but there was nobody home. Gardaí left a fake docket, which included a mobile number.
They later received two calls from a man calling himself Paul Matthews, the name on the courier delivery docket.
Subsequently, gardaí and members of the drugs squad searched the premises and found methadrome tablets with a street value of €139,695. Crawford, whose phone number was found on the gardaí’s mobile, admitted arranging the importation of the drugs.
In a follow-up operation at Lisnennan View, gardaí found a haul estimated to be worth €69,930.
Crawford said he had been a drug user since he was 15 but was now clean. Garda Paul Harte said he did not believe Crawford was the main person behind the operation.
Judge John O’Hagan jailed Crawford for five years and suspended two, backdating it to Nov 6 when he went into custody.