An international group which works to expose corruption in the procurement of natural resources is calling for an inquiry into the purchase of a house linked to a Manx registered business.

The £13m mansion in Kensington was bought through an Athol Steet company by Isabel dos Santos, daughter of a former Angolan president, according to The Times and reporters at Financial Uncovered.

Ms dos Santos is the eldest daughter of José Eduardo dos Santos who served as Angola’s president from 1979 to 2017 and is one of Africa’s richest women, with an estimated personal wealth of $2bn.

She is described by some in Angola as a ‘princess’.

Simon Taylor, a co-founder of non-profit investigators Global Witness who spent several years in the late 1990s digging into the Dos Santos regime, said: ‘The fact that this property appears to be owned secretly by Isabel dos Santos, through a company based in a tax haven, should raise all the red flags for corruption risk.

‘The National Crime Agency (NCA) would normally investigate the source of the funds used to buy a property – and if the funds cannot be determined as legitimate, the property should be seized under the unexplained wealth order regime.’

According to an investigation by Financial Uncovered journalist Christian Eriksson, which was printed in the Times, Ms dos Santos was unveiled as the owner of the house during a long-running issue regarding a planning application.

Financial Uncovered said: ‘The property was bought without a mortgage via an anonymous company registered in an offshore tax haven.’

It added: ‘UK Land Registry title deeds record the owner as Wilkson Properties Limited, a company incorporated in the Isle of Man.’

The company is registered on the four floor of Exchange House on Athol Street in Douglas and lists its agent in the island as the Fortress Management Services Limited.

The use of the term ‘tax haven’ will annoy the Manx government, which prefers to market the Isle of Man as a ‘low tax jurisdiction’.