An Ulster Unionist MLA has claimed there may be a second 'on-the-run' letter sent out by mistake following the collapse of the John Downey case.
Danny Kinahan said he had received information that another letter had been issued in relation to a case in Northern Ireland.
"It has come to our notice that there may well have been at least one letter a comfort letter if we call them that there has been issued wrongly in Northern Ireland," he told the BBC's The View.
"It may be that same letter has been used to stop prosecution or in defence of someone in a criminal court in Northern Ireland and we want to get to the bottom of it.
"We want to find out has this gone on."
Mr Kinahan was best man at one of the victims of the Hyde Park bombing in 1982 - Lt Anthony Daly.
Ex-IRA man John Downey had been a suspect in the attack, until the case against him collapsed at the end of last month.
Letters were sent to about 200 people by the Northern Ireland Office (NIO) after a search of police records to identify if they were wanted in connection with crimes.
In John Downey's case he was sent the letter in error after the computer system failed to reveal that he was sought by the Metropolitan Police for questioning over the Hyde Park bomb.