An Independent Monitoring Commission report which blamed the IRA for the theft of £26.5 million from a Belfast bank has been described as "rubbish" by Gerry Adams.

The Sinn Fein president also challenged the Irish prime minister, Bertie Ahern, to withdraw an allegation that the party leadership had prior knowledge of the December robbery or have him charged with conspiracy to rob and withholding information.

He said: "The taoiseach has crossed the line. It's time for him to shut up or put up."

"The report makes unsubstantiated allegations. If it wasn't so serious it would be even laughable."

Peter Robinson, the deputy leader of the Democratic Unionist Party, said that senior Sinn Fein figures should be arrested and asked what they know.

"Given what they [the monitoring commission] are saying about Sinn Fein members' involvement in the robbery, why have they not been arrested by the PSNI [Police Service of Northern Ireland] and questioned," he asked.