Maze escaper Gerry Kelly has been accused of going "on the run" again after Sinn Fein said he would not give evidence to a Westminster committee investigating amnesties for republican fugitives.
Deputy First Minister Martin McGuinness said that although the party had nothing to hide, officials would decline invitations to attend a NI Select Committee hearing in London.
The committee is investigating revelations that three British Governments since 2001 provided 228 IRA on-the-runs (OTRs) with letters stating they were no longer wanted for past crimes.
Mr McGuinness said he, party leader Gerry Adams and North Belfast MLA Mr Kelly met the Hallett review team last week.
"We see no point therefore in Gerry Kelly attending the Westminster Select Committee into the issue," he said.
TUV leader Jim Allister said Mr Kelly – a key figure in the the IRA's 1983 Maze Prison escape – had "chickened out".
"Not for the first time Gerry Kelly is on the run," he said.
"Happy to act as secret postman for the IRA in carrying their demands for OTR amnesty letters, he, who is so quick to demand inquiries that suit republican pet projects, is cowering in the shadows, unwilling to help uncover the truth over the OTR scandal. He and Sinn Fein have too much to hide.
"His refusal to attend is a challenge to the authority of the Westminster committee, which they must not dodge."
An inquiry by Lady Justice Heather Hallett was ordered by David Cameron after the collapse of a case against John Downey, who had been accused of the IRA's Hyde Park bomb in 1982.