Sinn Fein has urged British Prime Minister Mr Tony Blair to intervene personally to force the British Ministry of Defence to co-operate with the Bloody Sunday Inquiry.
The party president, Mr Gerry Adams, has asked Mr Blair to intervene in an argument over disclosure of MoD documents, photographs and film relating to Bloody Sunday.
Writing in yesterday's Irish News, he accused "elements of the British state" of subverting the Saville inquiry.
"Lawyers acting for the relatives have raised concern at the extent and importance of the material that the British MoD has not provided to the inquiry," Mr Adams said. "There are also serious concerns at the excuses being made by the British MoD for materials used at the time and which they claim have not been retained, or have been subsequently destroyed, or cannot be traced."
Earlier this year, counsel for the Ministry of Defence, Mr Ian Burnett, told the inquiry it was absurd to suggest the MoD was actively obstructing the inquiry's work. He said five full-time MoD civil servants were constantly assisting the inquiry.
He told the inquiry that because of "normal administrative processes designed to reduce the volume of paperwork preserved", the majority of documents in MoD files concerning the period of Bloody Sunday were destroyed.