Paul Quinn murder: Man arrested and police operation under way at farm
A man in his 50s has been arrested by gardaí (Irish police) investigating the death of Paul Quinn.
The 21-year-old was beaten to death in a barn at Oram, County Monaghan, in October 2007.
The BBC understands that specialist ground radar has been used in the search, near the border.
An object, possibly a vehicle, has been discovered. A digger has been brought it to excavate the item.
The arrest came during a major security operation at a farm near Castleblayney on the border between Monaghan and Armagh.
Supt Alan Cunningham said the search is likely to continue "for a couple of days".
"I would appeal to anyone with information and also anyone who was involved in the murder to make themselves known," he said.
"This investigation has gone on a number of years but we have continued to review any information we have received and this search is a part of that," he added.
The Quinn family have blamed the Provisional IRA for his death.
The government established Independent Monitoring Commission said those involved " included people who are members or former members, or have associations with members or former members, of the Provisional IRA."
This claim was denied by Sinn Féin.
The party's president Gerry Adams said a small handful of criminals who were "using the border for their own purposes" were responsible for his death.
Paul's mother, Breege, said she "felt glad and felt sad" when she received a call from the police.
"I felt sad because it just reminded me of that day, but I'm also very glad because it just goes to show that the gardaí haven't given up. They always said they wouldn't give up and that is proof," she said.
"From that very night to this day, the gardaí have been in constant contact with us to just let us know that they're still investigating the murder, that it will never be closed.
"We appreciate all the gardaí are doing for us in trying to get justice for our son."
She said police gave her some information about their operation.
"The gardaí rang to say they were scanning a field just on the border. They think there might be something buried in that field that was used for Paul's murder," she added.
Searches began at 09:00 BST on Thursday at the farm.
The man who was arrested is in his early 50s. He was detained in Castleblayney and is currently being held at Carrickmacross garda station.
Gardaí say the operation involves a large number of officers.