An Irish man accused of involvement in in Lithuania has been found guilty and sentenced to 12 years in prison.
Michael Campbell, 39, from County Louth was caught in an MI5 weapons sting operation in 2008.
He was convicted of supporting a terrorist group, illegal possession of weapons and attempted smuggling.
He denied the charges against him, saying MI5 had set him up and claiming he was a victim of entrapment.
His two-year trial in Vilnius began in August 2009.
Campbell was secretly filmed test-firing weapons in the Lithuanian countryside, and some of his private conversations were bugged.
In a secretly-recorded conversation, he was overheard talking about planting bombs in London.
He said he wanted weapons for use against "Brits".
Northern Ireland Secretary of State Owen Paterson welcomed the conviction.
"This is another excellent example of what can come from the high levels of co-operation between countries across Europe and beyond in combating terrorism," he said.
"I have no doubt that this will have dealt a blow to RIRA, but we are not complacent and we remain determined to do all that we can to bear down on those who are the enemies of the whole community throughout the United Kingdom."
Ceasefire
Campbell was convicted of supporting a terrorist group, illegal possession of weapons and attempted smuggling
The Lithuanians also suspect Campbell's older brother, Liam, of involvement in the gun-smuggling plot.
He is alleged to have been a senior member of the Real IRA and was one of four men found liable for the 1998 Omagh bombing. The civil case was taken by the families of some of the 29 people killed in the attack.
The Lithuanian authorities are trying to extradite Liam Campbell from Belfast, along with Brendan McGuigan, 30, from Omeath in the Republic of Ireland.
The Real IRA broke away from the Provisional IRA after they called a ceasefire in 1997.
Along with a number of other dissident republican groups, it is trying to derail the peace process.
Two years ago, it shot dead two young soldiers in Antrim.
Patrick Azimkar and Mark Quinsey were killed as they collected a pizza delivery outside their base.
