The public relations officer of the 32-County Sovereignty Movement, who is accused of explosives offences, told gardai he loaded bags from a trailer to a truck, the Special Criminal Court heard yesterday.
Det Garda John O'Connor said Mr Joe Dillon added: "I am not saying what was in the bags, but you know yourselves".
He was giving evidence in a "trial within a trial" on the admissibility of alleged statements made by Mr Dillon and three other men to gardai after their arrest for explosives offences last year.
Gardai found 28 bags of crushed fertiliser and five bags of it in granule form in one place and another bag of granular fertiliser at an unoccupied house in Bettystown, Co Meath.
The prosecution has claimed the fertiliser was intended for use in an explosives mixture. Mr Eamonn Flanagan (42), The Square, Skerries, Mr Seamus McLoughlin (66), Balkill Park, Howth and Mr Michael Blount (48), Bath Road, Balbriggan, have pleaded not guilty to having an explosive substance with intent to endanger life or to enable another person to do so at West Pier, Howth, Co Dublin, on January 5th, 1998.
Mr Dillon (53), of Greenlawns, Skerries, has pleaded not guilty to having an explosive substance at Windswept, Golf Links Road, Bettystown, Co Meath on January 5th last year.
The four have pleaded not guilty to having an explosive substance in suspicious circumstances on the same date. Det Garda O'Connor said he and Det Garda Sean Grennan interviewed Mr Dillon at Whitehall Garda Station on January 8th last year. Mr Dillon said he was a member of Sinn Fein and PRO for the 32-County Sovereignty Committee.
"I am quite happy with the peace process but want sovereignty to be the first item on the agenda, I have written to the president of the party. He shares my views and intends to bring it to the attention of the British and Irish governments," Mr Dillon said.
When asked if the 32-County Sovereignty Committee believed in violence, he said he went "out of his way to avoid transgression on the Irish right to self-defence and use of violence if it can be avoided". Mr Dillon told gardai he was an expert on constitutional law and said he "identified fully" with Mrs Bernadette Sands.
Mr Dillon agreed possession of explosives was a criminal offence. He i that said he had been in Bettystown on January 5th, 1998 but his presence there was "quite legitimate".
Det Garda O'Connor said Mr Dillon told gardai he had gone to an empty house at Bettystown and helped to load 10 or 15 "sealed, wired, white bags" from a trailer to a truck and other bags from a shed. He said Mr Dillon refused to sign notes of the interview and added that no threats were used. The trial continues today.