Cahill was then put in charge of importing arms for the IRA. He liaised with the NORAID group in America and with the Libyan dictatorship of Muammar al-Gaddafi to this end. In March 1973 he was arrested by the Irish Navy in Waterford, aboard the "Claudia", a ship from Libya loaded with five tons of weapons. Cahill was sentenced to three years imprisonment by the Irish Special Criminal Court. Cahill stated at his trial that, "If I am guilty of any crime, it is that I did not succeed in getting the contents of the "Claudia" into the hands of the freedom fighters in this country".