The Flood Tribunal is due to resume in Dublin Castle this morning.
Building developers Tom Brennan and Joe McGowan are due to be questioned about a cheque for £15,000 given to Ray Burke in 1974.
The cheque was listed in their accounts as being "for planning matters".
The pair were awarded compensation of £1.9m after Dublin County Council refused to grant them planning permission for a site at Mountgorry in Swords, Co Dublin.
The 90-acre site was subsequently sold for development and is now owned by Thomas and Michael Bailey, who have already testified to the tribunal.