The inquiry into the Edinburgh trams fiasco could lead to criminal prosecutions, according to the judge chairing the investigation.

Lord Hardie said his probe must not rule on, and has no power to determine, any person's civil or criminal liability.

He said "that does not mean that nobody will be prosecuted as a consequence of their involvement in the project", however.

Lord Hardie spoke as he revealed he had started interviewing members of the public about the controversial project.

Detailed statements are being taken by councillors, residents and business owners affected by the development.

Lord Hardie said: "Any question of prosecution will ultimately be a matter for the Lord Advocate and Crown Office and Procurator Fiscal Service (COPFS), and their decision will depend upon the availability of evidence supporting such a decision.

"As far as I am aware, neither the Lord Advocate nor COPFS has determined that nobody will be prosecuted.

"Indeed, it might seem to be premature to express such a view without considering the terms of the inquiry report which will be written after the conclusion of the evidence sessions in public.

"Furthermore, any question of civil liability must be determined by an appropriate court, having jurisdiction to do so."

The Scottish Government ordered the inquiry to establish why the project was delayed, cost more than its original budget and delivered a far shorter route than was first planned.

The scandal-hit project cost £776m, more than double the estimated cost, after six years of legal wrangling and six miles shorter than originally planned.

The inquiry team, who have also sifted through six million documents as part of the investigation, launched a formal call for evidence in May last year.

Lord Hardie added: "If the Edinburgh Tram Inquiry is to provide a truly comprehensive account of the reasons behind, and the consequences of, the failure of the original project to be delivered on time and to budget and scope, then the evidence of those members of the public directly affected will be an essential part of my deliberations.

"This includes all of the evidence already submitted by the public, supplemented by the detailed statements that we are now in the process of obtaining.

"The inquiry team has already begun to make contact with certain members of the public to seek their assistance. I have been heartened by the response received so far. The contributions of all who participate will be invaluable in ensuring that this inquiry makes robust recommendations for future infrastructure projects of this scale and significance."

He said public co-operation is vital to ensure lessons are learned to avoid similar consequences in other project.

Lord Hardie said this was particularly important given that councillors are likely to consider extending the tram line following next year's local authority elections.

Members of the public wishing to provide evidence to the Inquiry are asked to contact the Inquiry team byc calling 0300 244 1940, emailing info@edinburghtraminquiry.org or by writing to the Secretary of the Inquiry, 1st Floor, Waverley Gate, 2-4 Waterloo Place, Edinburgh EH1 3EG.