Martin McGuinness has told unionist parties they need to either "put up, or shut up" on allegations of Sinn Féin links to criminality.
Northern Ireland's deputy first minister says if anyone has evidence linking Sinn Féin to criminal groups, they need to bring it to the police - or drop their accusations.
McGuinness says he told other parties they must stop claiming Sinn Féin has links to an active IRA, unless they have proof.
“If anybody has any information whatsoever, about any party in government, they should put it up on the table and more importantly they should put it to the PSNI.
“In other words, I told them it’s now time for them to put up or shut up,” he said.
He was speaking as the five major parties began a new round of crisis talks aimed at ensuring Unionist parties to return to government.
The Democratic Unionists and Ulster Unionists say the issue of paramilitary activity is crucial to their participation in any talks.
Further discussions are taking place to try to save Northern Ireland's power sharing assembly.
They are being held by the British and Irish governments.
DUP leader Peter Robinson, who has only just been discharged from hospital, has this message.
The 66-year-old was admitted to hospital after suffering a reaction to prescribed medication.
He stood aside as First Minister, along with three other DUP ministers.
Ulster Unionist leader Mike Nesbitt is also urging a common goal.
The Stormont Assembly has been shaken by allegations that the Provisional IRA - which is meant to be dissolved - is still operating.
It has prompted the Northern Secretary Theresa Villiers to commission an assessment of paramilitary organisations.
Ms Villiers said the assessment, which will be published by mid-October, will be available to inform the parties' discussions and conclusions in the cross-party talks.
While Foreign Affairs Minister, Charlie Flanagan, said the exercise will be "a once-off exercise completed over the coming weeks and is intended to assist the parties in the talks in their collective consideration of how the impact and legacy of paramilitary activity should best be addressed".
