A DIAMOND ring worth £1.1m has been seized by the National Crime Agency in a case involving the UK's first Unexplained Wealth Order (UWO).

The Cartier piece, originally bought by Azerbaijani banker Jahangir Hajiyev, has been held by investigators as they work to establish how it was paid for.

Two UWOs were granted against the financier's wife Zamira Hajiyeva - who owns Mill Ride Golf Club - concerning properties worth a total of £22 million under so-called McMafia laws.

Hajiyeva has refused requests to explain the source of her extraordinary wealth.

If she continues to fail to reveal the origin of her fortune, the courts could seize her properties including a £11.5m five-bedroom home in Knightsbridge and a £10.5m golf and country club in Ascot.

The powers, which came into force at the beginning of 2018, allow investigators to look into the source of wealth of politically exposed persons (PEP).

These are people from outside the European Economic Area in a position of power that makes them liable to bribery or corruption, or those with suspected links to serious or organised crime, who are unable explain the source of their wealth.

UK authorities want to know how the couple could afford to buy their large house in Knightsbridge as well as a golf club in Berkshire.

The diamond ring, which has a retail value of £1.19m and was bought by Mr Hajiyev at Harrods in 2011, was seized from a jewellers where it had been sent for repair.

It will be held for six months while investigators carry on their work.

The NCA has already seized 49 items of jewellery worth more than £400,000 from a London auction house, where they were being valued for Mrs Hajiyeva's daughter in November.

Mrs Hajiyeva, 55, is facing extradition to Azerbaijan over allegations of embezzlement.

Her husband was the chairman of the state-controlled International Bank of Azerbaijan from 2001 until his resignation in 2015, and was subsequently sentenced to 15 years for fraud and embezzlement.

When Mrs Hajiyeva unsuccessfully attempted to overturn a UWO in October, her lawyers claimed her husband's conviction was the result of a "show trial" and that his guilt "had been determined by the presidential administration in advance".