Lord Fraser has outlined how he intends to conduct his inquiry into the spiralling costs of the new Scottish parliament building.

Original costs for the project were estimated at £40 million. However, after a number of increases, the most recent estimate is £375 million.

Evidence sessions will begin next month with the inquiry sitting for three days in the first week and four days per week after that until Easter.

All of the sessions will be televised, while documents given as evidence will appear on a dedicated website. The final report is due in the summer of next year.

"I cannot but recognise the intensity of interest and concern over this issue across Scotland," said Lord Fraser.

"Neither the Scottish executive nor MSPs should underestimate that.

"Since the first minister announced his invitation to me, I cannot walk through Edinburgh, sit on a train or go to any event anywhere in Scotland, public or private, without being asked about the inquiry or being told in no uncertain terms how I should conduct it."

The number of emails from whistleblowers bad been "extraordinary", he said.

The inquiry will first focus on events concerning the Holyrood project and then on the material received.

The Conservative peer has said that no evidence given will be used against witnesses in criminal proceedings, but that they could be recalled if he feels they are holding anything back while on the stand.

"There will be the rights of the Scottish parliament or for the earlier period the rights of the Westminster parliament to summon such persons to give further evidence and should I have concerns about the veracity of any witnesses' evidence I shall not hesitate to recommend appropriate action," he warned.

Independent MSP Margo MacDonald called on Whitehall to cooperate with the investigation.

"From what I heard today I believe Peter Fraser will manage to walk the tightrope between the credibility that the inquiry has to have with the public by being as transparent and accessible as possible, and the absolute requirement on him to ensure that no contractor or consultant or anyone concerned is given the opportunity to open up legal action against either the inquiry or the parliament," she said.