Northern Ireland Reaction: Sinn Féin welcomed the decision on the three men, while the DUP justice spokesman, Mr Ian Paisley jnr, described the verdict as "jungle justice at its worst".
Mr Paisley said, regardless of the result, it was clear there were connections between the IRA and the FARC paramilitary grouping in Colombia.
He queried whether the Irish Government or "others" might have played some role in the outcome. "One has to wonder what sort of political pressure has been applied behind the scenes to ensure this verdict.
"The ramifications of a guilty verdict would have had massive repercussions, and we have seen before the lengths some will go not to upset the apple cart."
Mr Paisley said no one believed that the three men were tourists in Colombia.
"Whilst Monaghan, Connolly and McCauley have been let off, it is clear that links exist between the Provisional IRA and the FARC, not least in the exchange of terrorist tactics.
"Provo tactics, honed against the people of Northern Ireland over a 30-year period, have already brought death and destruction IRA-style to the streets of Bogota and Medillin.
"There are still questions which Sinn Féin/IRA must answer, such as the extent of their links to worldwide terrorist groupings, what their representatives were doing travelling deep in FARC territory on illegal documents and what is their connection to the despicable Castro regime in Cuba?
"There will, no doubt, now be homecoming celebrations for these men. It will be interesting to see what political party is at the FARC jungle farce in numbers to welcome them home."
The Sinn Féin policing spokesman, Mr Gerry Kelly, said it was now vital that the men be afforded a safe escort out of Colombia.
He said the verdict would bring huge relief to their families, although there was considerable anger that the men were held in the first place.
"Despite the obvious collapse of the prosecution case last year it was never certain that the men would be released and sent home. There was always a concern due to the pressure on the judge from the Colombian government and the military."
Mr Kelly said the men were subjected to an unfair legal process. "Their basic rights were denied. There was extensive false reporting in the media, and the investigation was closed before key witnesses were interviewed. There was also ongoing political interference in the trial.
"This whole episode has been a travesty for the men and their families, and they should now be allowed to get on with their lives in peace," said Mr Kelly.
The Sinn Féin president, Mr Gerry Adams, added: "The last three years have been very difficult for the men and their families. They have been pilloried in the media, their case subject to huge prejudicial commentary and the men's lives have been in constant danger.
"And, of course, this case has been used to try and destabilise the Irish peace process.
"I want to congratulate the families, those involved in the Bring Them Home campaign and the international observers, all of whom campaigned to ensure that this verdict happened."
Ulster Unionist Assembly member Sir Reg Empey said it seemed inconceivable that the men were tourists, and asked why they had false documents if they were legitimate visitors? "I don't think there are very many people in Northern Ireland who believe they were tourists."