The hardline Ulster Unionist MP, Mr Jeffrey Donaldson, last night accused the British government of introducing a new definition of decommissioning as part of a carefully arranged deal between the IRA and the IICD.
"It is emerging that the government prepared a new decommissioning scheme last week, signed off by the Secretary of State on August 2nd before the careful choreography between the IRA and Gen de Chastelain," he said.
London confirmed last night it had agreed to a request from Gen de Chastelain to introduce new regulations on decommissioning to give the body more flexibility.
On the method of decommissioning, the scheme states: "The method by which arms are to be made permanently inaccessible or permanently unusable, so that they are completely beyond use, is to be determined by the Commission after consultation with the contact person or a person acting with him."
A Northern Ireland Office spokeswoman denied Mr Donaldson's claims that the introduction of a new system was part of a choreographed stunt.
"It was not done in a bid to get a statement from the IRA. We simply responded to a request from Gen de Chastelain and we did it in good faith. There was no deal in the offing," she said.