AN INVESTIGATION has been launched after thieves broke into the offices of the Edinburgh tram inquiry, reportedly stealing a number of items including a laptop computer.

The incident took place at the Waverley Gate building on Princes Street overnight between Thursday evening and Friday morning.

Police investigating the break-in said the stolen computer had been "suitably encrypted".

A spokesman for the Edinburgh Tram Inquiry said: "We can confirm that the stolen computer equipment incorporated the highest levels of encryption in line with Scottish Government security policy.

"Work will continue at the Edinburgh Tram inquiry in accordance with the published order of events."

The city centre office building is currently home to staff working on the public inquiry into the construction of Edinburgh's trams, which were delivered late and millions of pounds over budget.

It is not known whether information gathered as part of the public inquiry has been lost.

Police said it would be inappropriate to comment further while inquiries were continuing.

Edinburgh's tram service began running in May 2014 but only after six years of disruption and a bitter dispute between the city council and its contractor.

The trams inquiry, announced in June 2014, has been reviewing evidence and identifying potential witnesses.

In December, Lord Hardie, the judge chairing the inquiry, revealed that some key witnesses had refused "point blank" to give evidence while others "just didn't answer letters".

As a result the Scottish Government upgraded the inquiry from non-statutory to statutory, granting Lord Hardie the powers to compel witnesses to appear.

The Edinburgh tram route cost £776 million and covers 8.7 miles (14km) from the New Town to Edinburgh Airport.

In the decade since the first money was allocated to the project, the price doubled, the network halved and it took twice as long to build as originally planned.