Sinn Féin has insisted "claims and allegations" of a republican espionage plot would not undermine the peace process.
As detectives questioned a former diary secretary in Mr Trimble's private office at Stormont, Sinn Féin leader Mr Gerry Adams again denied that any member of his party was involved in spying.
Following an address to Irish Americans in New York last night, he said the allegations would not destroy the Belfast Agreement.
"People know that this is a process of change, they know that there is resistance to that change and they know that is going to take time to sort all of these matters out," he said. "They wonder why there is a focus on only one side of things and what are merely claims and allegations".
Mr Trimble last night warned the latest arrest could have major repercussions for the Agreement.
The civil servant, who is from the Catholic Andersonstown district of west Belfast, was arrested at Castle Buildings inside the Stormont estate.
He was moved there to work for one of Secretary of State Mr Paul Murphy's junior ministers, Mr Ian Pearson, after the devolved institutions were suspended last month.
Mr Murphy informed Ulster Unionist Party leader Mr David Trimble and SDLP leader Mark Durkan, the former Deputy First Minister, hours after the arrest late on Wednesday afternoon.
PA