Lawyers for Sean Hoey have said they may take action against the father of one of the Omagh bomb victims.
Mr Hoey (38) from Jonesborough, Co Armagh, was acquitted on Thursday of murdering 29 people in the 1998 Omagh bombing after spending four years in custody.
His solicitor, Kevin Winters, said claims made by English lawyer Victor Barker, whose 12-year-old son James was one of 29 people who died in the 1998 bombing, may be actionable.
"Sean Hoey refutes completely the allegations made by Victor Barker when he persists in blaming him for Omagh," said Mr Winters.
"Mr Hoey is an innocent man and the court's judgment is an emphatic endorsement of his innocence.
"We will not hesitate to use the courts again to protect his name."
Mr Barker said he had consulted with his lawyers in light of Mr Winters' statement.
"I believe the comments I made were a fair and accurate reflection of events reported in the court," he said.
He added: "I also made it clear that I, like everyone else, must abide by the decision of the court."
Mr Hoey also said he may launch a civil lawsuit against the prosecuting authorities on the grounds of malicious prosecution.
Meanwhile, Chief Constable Sir Hugh Orde, speaking at PSNI headquarters in Belfast, admitted he believed it highly unlikely there would ever now be a successful prosecution for the Omagh bombing.
He said: "In my judgment, the only way we will see a successful prosecution in a criminal court is if people stand up and say 'This was committed by X and I will tell you how it happened'.
"If they do that they will have my total support and total protection."
Sir Hugh said he did not regret launching the case, adding: "I think what Detective Chief Superintendent Norman Baxter (the man in charge of the Omagh inquiry) did with what he had was outstanding."
First Minister Ian Paisley said the hunt to find the Omagh bombers must go on.
"We need at this time to take care that we do not make this matter worse for those that are sorrowing," he said.
"People are saying that there will never be a (another) trial and they (the bombers) will never be brought to justice.
"This is completely a victory for the people who did this vile deed. The doer of this deed will have to be brought to justice."