Detective Garda Alan Monaghan said gardai had information there would be a drugs handover. They saw a taxi in which Fannin was a passenger park in the grounds of a pub.
An Audi parked nearby and a man got out and walked over to the taxi. There was a conversation and the man got back into the Audi and drove off.
Gardai intercepted the taxi at Laytown and found a small amount of drugs on Fannin, who appeared anxious. They searched the taxi and discovered a bag containing cannabis worth €116,000.
Det Garda Monaghan said Fannin took responsibility at the scene for the items and then retracted his admission.
Padraig Dwyer, defending, said Fannin had worked for a significant time, but had declined into drug addiction to the extent where he was acting as a courier to pay off a drug debt.
He said Fannin was not going to benefit from the drugs apart from having his debt wiped out.
Mr Dwyer said Fannin said he was drugs-free and was using his time in custody well.