Chancellor George Osborne’s family business made £6 million in a property deal with a developer based in a tax haven, a Channel 4 News investigation has found.

Wallpaper firm Osborne & Little teamed up with a secretive corporation in the British Virgin Islands, to draw up plans to redevelop its former London headquarters into housing.

The companies jointly applied for planning permission for around 45 flats and houses, and once given the go-ahead, Osborne and Little sold its site to the offshore firm for £6,088,000.

A legal expert shown contracts obtained by Channel 4 News said Osborne & Little must have known the developer was based offshore, and had the potential to avoid millions in tax.

At the time, the Chancellor was the beneficiary of a family trust that owned at least 15% of Osborne and Little, so would have personally benefitted from the sale.

It is not known what the Chancellor’s personal stake was.

The deal calls into question his commitment to clamping down on offshore firms avoiding tax, a practice he has gone on to publicly condemn as “morally repugnant”.

The offshore company, called Nightingale Mews Incorporated, went on to redevelop the site, in Denning Mews, Clapham, and is estimated to have avoided up to £2 million in tax on its profits.

There is no suggestion the Chancellor, or Osborne & Little avoided any tax in the deal, or that they or offshore property developer Nightingale Mews Inc. did anything illegal.

The Channel 4 News revelations come as the Chancellor prepares to deliver his Summer Budget, which is expected to include far-reaching cuts to services in a bid to reduce the deficit.

In contrast, campaigners are urging him to regain funds by tackling tax avoidance by the rich

Details of the property deal emerged in a series of documents obtained by Channel 4 News. They show the wallpaper business entered into an agreement with BVI-based Nightingale Mews Incorporated to redevelop its headquarters in Temperley Road, Clapham, south London, in 2004.

A confidential contract stated that the two firms would submit a joint planning application to Wandsworth Borough Council for around 40,000 square feet of residential housing. The gated mews street would be named Nightingale Mews.

Planners approved a scheme for 16 homes and 26 flats in January 2005, and a deal for Osborne & Little to sell the land was signed in May 2005 by George Osborne’s father Sir Peter Osborne.

Tax haven

Barrister David Quentin, a senior adviser to the Tax Justice Network, said Osborne & Little must have been aware that Nightingale Mews Inc. was based in a tax haven.

He said: “It’s quite clear that we’re dealing with an offshore company. If you look at this agreement, you see that the buyer company is named and then it’s expressly described as incorporated in the British Virgin Islands.”

He added, by being based offshore, the company could have avoided any tax on profits it made. “Instead of paying UK tax on that profit, it would be able to realise that profit tax free,” he said.

£8m profit

The development was later renamed Denning Mews, with analysis of Land Registry records showing the upmarket flats and houses were sold for around £20m. It is estimated the profit may have been up to £8m, with the developer able to legally avoid up to £2m in corporation tax by being based in a tax haven.

Following the sale of the new homes, Nightingale Mews Inc. was dissolved, in 2010. It is virtually impossible to know who was behind the British Virgin Islands company, which is registered to a PO Box in a legal office on the Caribbean island of Tortola.

As well as branding “aggressive tax avoidance” as “morally repugnant” in his 2012 budget speech, George Osborne has promised to clamp down on properties owned by offshore firms.

The government introduced an annual levy on those that were, but campaigners say the fee, which raised just £73m last year, has done little to dissuade wealthy investors.

Channel 4 News asked the chancellor if he was aware of the deal, and aware of the agreement to sell to an offshore company – and put to him that the taxpayer could have lost millions of pounds. His office refused to answer any questions and said only: “This is a totally bogus and desperate story.”

‘Commercial basis’

Sir Peter Osborne, managing director of Osborne & Little, said the wallpaper company “is not in the business of property development and simply sold the property on a commercial basis”.

He said all relevant taxes on the sale of the London site were paid, adding: “The company retained no benefit in any future development of the property and the directors have no knowledge of the success or otherwise of the redevelopment.”

Sir Peter said the directors of Osborne & Little “cannot comment on the tax affairs of another company, whose tax residence, rather than country of incorporation, is not known to them”.

An analysis by Channel 4 News shows 73,853 commercial and residential properties in England and Wales were registered in tax havens since 2009.

While half the homes on Grosvenor Crescent in London’s Belgravia – named by a Lloyds Bank study as the most expensive street in the country – were found to be registered to tax havens.