And we can also reveal that a secret meeting was held in London in the wake of the Castlereagh and Stormontgate scandals to stop the top loyalist agent from standing down.

The paramilitary 'brigadier' who was met in the English capital remains a member of the UDA's ruling 'inner council'.

Sunday Life knows his name - but is not publishing it.

His role as an agent was revealed by a senior and credible source.

Now, a prominent nationalist politician has called on State organisations and paramilitaries - both republican and loyalist - "to come clean on how deeply involved one was with the other".

Alex Attwood, a former member of the Policing Board, made his call as the Eames-Bradley Consultative Group on the Past continues its work.

Its report and recommendations are due in the summer or early autumn.

"I think there were a lot more agents involved in more activities and at a much higher leadership level," SDLP MLA Attwood told this newspaper.

"Many people died because of that - across the board, security force and civilian."

The informer met in London is one example of how agent-running reached into the highest levels of paramilitary organisations.

The 'CHIS' - meaning covert human intelligence source - has operated at the heart of the UDA for years.

His threat to end his agent role was part of the nervousness and turmoil that resulted from the major security breaches of 2002.

Now, as the Eames-Bradley group looks into the past, Mr Attwood believes it is beginning to "get its head round the vastness of its work".

He wants its report when published to reflect "daring thinking" and argues that the consultative group should be given all the help they need to "propose radical ideas".

The group has already had access to the Stevens team - which investigated the murder of Belfast solicitor Pat Finucane and other alleged acts of collusion.