The telecoms tycoon Denis O'Brien and a number of other witnesses are expected to give evidence to a new session of the Moriarty (Payments to Politicians) tribunal, due to open tomorrow.
The session is expected to last until the middle of March and the tribunal's report is now unlikely to be published until late 2007.
The tribunal is to inquire into a £4.3 million stg property deal in Doncaster in August 1998 which Mr O'Brien has told the tribunal was his and had nothing to do with the former minister for transport, energy and communications, Michael Lowry. Mr Lowry has also said he had no connection with the deal.
The tribunal began to look into the matter after a report in The Irish Times quoted a September 1998 letter to Mr Lowry from the English solicitor who acted for the purchaser in the deal, Christopher Vaughan. Mr Vaughan referred to Mr Lowry's "total involvement" in the transaction.
Mr Vaughan has since told the tribunal he wrote the letter when under a misapprehension. However he has not agreed to travel to give evidence.
The tribunal, in its private inquiry phase, discovered another mention of Mr Lowry in a London solicitor's memo of a meeting in September 2002. Ruth Collard, of Carter Ruck solicitors, recorded accountant Denis O'Connor telling her that Mr Lowry was connected with the Doncaster deal, and had been in a room during discussions on a lease involving the vendor, Ken Richardson, and Northern Irish businessman Kevin Phelan.
Mr O'Connor has since told the tribunal the solicitor must have made a mistake. Both he and Ms Collard are expected to give evidence in the coming session.
Mr O'Connor has worked for Mr Lowry in his dealings with the tribunal but has said he was at the London meeting at the request of Denis O'Brien snr.
Mr O'Brien snr was involved in seeking to resolve disputes that arose with Mr Richardson in the wake of the Doncaster deal. He is expected to be called to give evidence. The transaction involved the purchase of Doncaster Rovers Football Club (DRFC) Ltd from Mr Richardson and a Mark Weaver. The company had a lease on the football stadium in Doncaster, which is to be redeveloped. Mr Phelan noted the potential of the deal. An unrelated Dublin accountant, Aidan Phelan, fronted the purchase. Mr O'Brien jnr has been on the board of DRFC Ltd since April 2003.
It is not expected that Mr Weaver or Mr Richardson will attend to give evidence. Mr Richardson has served time in jail for seeking to have the stadium burned down. Kevin Phelan is also not expected to attend.