The failed cross-party talks chaired by Richard Haass and Meghan O'Sullivan cost a total of almost £250,000, it has been revealed.
The Haass talks - which ran between July and December - totalled £243, 474, the Office of the First and Deputy First Minister unveiled on Monday.
The breakdown of costs included travel and accommodation - which made up the largest proportion - adding up to £133,000.
Admin added a further £89,000 to the bill, with an additional £21,800 going towards the "remuneration of support staff".
But former US diplomat, Dr Richard Haass, and his co-chair Professor Meghan O'Sullivan, provided their services free of charge.
The weeks of talks last year ended in deadlock, with the five main political parties failing to reach agreement on dealing with the past.
The proposals - which failed despite a last ditch draft on New Year's Eve - had aimed at securing long-sought resolution to outstanding peace process issues in Northern Ireland.
Dr Haass and Professor O'Sullivan had been given until the end of the year to strike a deal on flags, disputed parades and the legacy of the Troubles, but was unable to attain consensus among Stormont's five main parties.
Among the many political sticking points, the document deals with areas covering new arrangements in dealing with parades, public events, culture and identity along with 'contending with the past'.