A 47-year-old Dundalk man is to be charged in the Special Criminal Court this morning in connection with the Omagh bombing.
He will be the first person to be charged in connection with the bomb, which killed 29 people and injured more than 200 six months ago.
Intense security will surround the man's appearance in the Green Street courthouse in Dublin. It is expected he will face more than one charge, but will not be charged with murder.
The man was one of three men arrested by gardai on Sunday and taken to Monaghan Garda Station for questioning.
Last night a Garda spokesman said: "As part of an ongoing investigation, a man who had been detained under Section 30 of the Offences Against the State Act is to appear at the Special Criminal Court on Wednesday morning."
The RUC press office issued a statement repeating the information. The statement added that the man would face a number of charges.
Gardai investigating the bombing had discussions with the office of the Director of Public Prosecutions (DPP) last night, before a decision was made to charge the man.
Seven other men, including the chairman of the 32-County Sovereignty Movement, Mr Francie Mackey, were still being held in custody last night on both sides of the Border, after a series of co-ordinated arrest operations.
Four men from south Armagh who had been arrested were released by the RUC last night, and two men were still in custody in Carrickmacross Garda station.
The development represents a significant breakthrough for both police forces.
Last month the Garda Commissioner, Mr Pat Byrne, said the joint RUC-Garda investigation into the bomb attack had made good progress. The Commissioner said he was confident that people would be prosecuted for the bombing.
The investigation had seen an unprecedented level of co-operation between the two police forces, he said, and the investigation would now concentrate on proving those suspected of the bombing were responsible.
The bomb went off at 3.10 p.m. on Saturday, August 15th, 1998, in a crowded shopping street in Omagh, killing 29 people and injuring more than 200 others, many seriously.
The dead included three generations of one family, a woman who was pregnant with twins, her baby and her mother, three children from Buncrana, Co Donegal and a student and group leader from Spain.
A warning had been given by a caller using a recognised code word of the Real IRA, but this had been misleading, according to the RUC.
Investigations later established that the car in which the bomb had been planted had been stolen a week earlier in Carrickmacross, Co Monaghan. However, it was thought the device could have been prepared north of the Border and the bombers could have been guided to their target by associates in the Omagh area. The Chief Constable of the RUC, Mr Ronnie Flanagan, said later that the bomb's timing power unit resembled six others which had been used in attacks by the Real IRA, and which had all been packed into identical plastic sandwich boxes.
In the wake of the blast, the Government announced tough anti-terrorist measures, including the seizure of land or other property used for storing weapons or making bombs.
The Taoiseach, Mr Ahern, said he believed the Real IRA had been responsible for the bombing, and said they would be "crushed".
