An Oireachtas committee investigating cost overruns on Iarnrod Eireann's new signalling project is likely to call more than 100 witnesses at hearings in September.
It is understood that certain advisers to members of the Oireachtas Joint Committee on Public Enterprise and Transport believe evidence recently presented to the inquiry supports findings in the study last year which led to its establishment.
That preliminary study, by consulting group PricewaterhouseCoopers, concluded that Iarnrod Eireann's signalling contracts failed to meet any of its procurement objectives.
Costs would rise to £25-£40 million (€32-€51 million) from a projected £14 million, the consultants said.
Iarnrod Eireann is understood to have spent £16 million on the project already.
The committee's chairman, Mr Sean Doherty TD, is expected to make an opening statement on the inquiry at a public hearing on Wednesday.
He declined to comment on the contents of his statement, which is expected to give a broad outline of the inquiry's scope and objectives.
Formal hearings begin on September 10th. The committee is expected to sit in session five days a week for three weeks.
It has appointed a British consultant, Dr John Hill, to advise on cabling issues. A barrister, Mr Frank Clarke SC, is also acting for the committee, as well as an accounting firm, Chapman Flood Mazars.
Committee members are empowered to compel witnesses to appear before it, but it is understood that all those contacted have expressed willingness to attend the hearings.
The last time an Oireachtas committee held such an inquiry was in 1999 when the Committee of Public Accounts examined large-scale evasion of DIRT.
The committee is likely to investigate the departure of four Iarnrod Eireann figures to Dublin firm Modern Networks Ltd (MNL) after the contract for the signalling project was signed with it.
Its members are also likely to examine cost increases linked to work on a telecoms network laid along the railway for Esat Telecom, the firm established by the businessman, Mr Denis O'Brien.
The Mini CTC (centralised traffic control) system was designed to replace the mechanical signalling system with an electronic one. But despite the cost overruns, the project remains incomplete. It requires 130km of cable-laying and physical connection to each station on the network.
A recent rail safety audit by British group International Risk Management Services said the postponement of the project was causing a "major problem" to the engineers to maintain the existing system.
Iarnrod Eireann moved last month to terminate its contract with the British-based group Alstom.
MNL is in examinership after incurring losses since last year which it attributed to difficulties encountered on the Iarnrod Eireann project. It said in the High Court that it could not pay its debts because Iarnrod Eireann had failed to pay it.
