Around £10,000 was found hidden in the underwear of an Italian man as he boarded a flight out of the country at Belfast International Airport.
Officers from the UK Border Agency stopped and searched the man last Friday.
When questioned he was not able to provide a reasonable explanation for having the large sum of money stashed in his underwear, pockets and wallet.
The money was detained under the Proceeds of Crime Act. It will only be returned if the man can prove in court that the money came from a legitimate source.
The man elected not to continue on his flight to Rome.
Maggie Eyden, UK Border Agency Assistant Director for Northern Ireland, said: "UK Border Agency officers are working hard at all our ports to prevent drugs, contraband or the potential proceeds of crime from entering or leaving the UK.
"Where we suspect that cash may be linked with criminal activity, we have the power to seize it and it will only be handed back if it is later proved to be legitimate."
© UTV News