BRITISH Customs and Excise officers at Heathrow Airport arrested an Irishman yesterday on suspicion of being involved in the illegal exporting of about £300,000 when he attempted to board a flight for Amsterdam, Holland.
Mr John Gilligan is being questioned under the British Drug Trafficking Act.
Another man, Mr Michael Cunningham, was also detained on his way to boarding the same flight to Amsterdam.
He is being questioned by officers in connection with the find; but he has not been formally arrested.
Both men were being held at a secure unit in the Customs and Excise building at Heathrow's terminal 4.
Earlier, a spokesman for Customs and Excise said the two men had attempted to board the flight for Amsterdam at about 2 p.m. yesterday when their hand luggage was searched.
Officials became suspicious he said, when the men could give "no sensible explanation" for carrying such an unusually large sum of money.
"For someone to be carrying that amount of money and not to give a sensible explanation for its origin or legitimacy, is unusual," he said.
It is understood that the journey originated at Heathrow and was not part of a connecting flight to Amsterdam.
The Customs spokesman said both men would now be subject to inquiries by the investigation service branch of Customs and Excise to establish "the legitimacy or otherwise" of the money found in their possession.
The inquiry, however, would not form part of any outstanding investigations in the Irish Republic concerning Mr Gilligan or his companion. However, the spokesman said the officers conducting the investigation would not hesitate to "accede to any reasonable request" by either the British or Irish police to have access to the two men once their investigation had been completed.
Customs and Excise officials said last night that there was no legal limit to the amount of money which could be carried by a passenger in a private capacity while travelling on an airline. They also pointed out that under civil legislation, Customs officials are entitled to hold the money found until such time as any formal charges may be made.
If formal charges are brought to court under the Drugs Trafficking Act, the court would decide to either return it to its owners or on the basis of the Customs and Excise accusation, retain it in safe custody.