Tony and Cherie Blair saved £312,000 in stamp duty when acquiring a £6.45m townhouse in London, leaked documents show.

The former Labour prime minister and his barrister wife purchased the property as an office for her business in 2017 by buying the offshore firm that owned it.

Cherie Blair told the press that the vendor, based in Bahrain, had insisted the building was sold in this way but they had brought it under UK control.

She was keen to point out that they would be liable to pay capital gains tax if they opt to sell it.

According to Cherie Blair, her husband’s involvement in the transaction was solely aimed at ensuring they could raise the mortgage required to acquire the property, by using their joint income and capital.

The revelation is contained in the Pandora Papers, a leak detailing the work of companies offering offshore financial services in the British Virgin Islands, Singapore, Panama, Belize, Switzerland and other countries.

The BBC says that its Panorama TV show in a joint investigation with the Guardian and other media partners have had access to almost 12 million documents and files.

Since leaving Downing Street in 2007, the Blairs have built up a significant property portfolio. Altogether they are reported to have spent close to £40m on 39 properties.

It is understood that no laws were broken in acquiring the property on Harcourt Street office but Tony Blair had previously been critical of tax loopholes.

He once said, “The tax system is a haven of scams, perks, city deals and profits”.