The BBC has won a challenge to identify a London mansion at the heart of the latest Unexplained Wealth Order (UWO).
The property is the family home of one of the members of Kazakhstan's political elite, Nurali Aliyev.
The home on The Bishops Avenue, Hampstead - known as "Billionaires' Row" - is owned by offshore companies.
It is one of three homes worth more than £80m owned for the benefit of Mr Aliyev and his leading Kazakh politician mother, Dariga Nazarbayeva.
The National Crime Agency suspects all three of the mega properties in London were bought with riches embezzled by Mr Aliyev's notorious and now dead father.
Rakhat Aliyev once styled himself "Godfather-in-law" and was accused of crimes including murder, before his own death in prison.
Mr Aliyev and Dr Nazarbayeva have denied all wrongdoing - saying they can prove independent and legitimate wealth for their UK property investments.
What are Unexplained Wealth Orders?
Unexplained Wealth Orders are one of the UK's newest tools in the fight against suspected criminal money invested in property.
National Crime Agency investigators can use UWOs to require owners to disclose how they managed to buy a luxury home.
If they do not agree with the explanation, they can then ask the courts to confiscate it.
What are the three properties?
- A high security mansion at 33 The Bishops Avenue - one of the most expensive roads in Britain. The 10-bedroom home has an underground pool, "tropical showers", a glass domed roof, a dedicated cinema and separate quarters for staff
- A mega apartment in a luxury secure development at 21 Manresa Road, Chelsea, constructed following a multi-million pound merger of two already enormous flats
- Another secure mansion at 32 Denewood Road, Highgate, a private cul-de-sac with views over one of London's most exclusive golf clubs
Each of the homes is owned by companies incorporated in three tax havens - Panama, Anguilla and Curacao in the Caribbean.
The properties' fate will be decided in a major court battle that began at the High Court on Tuesday.
Who are the Aliyev family?
Mr Aliyev describes himself as a tech entrepreneur and investor. His grandfather, Nursultan Nazarbayev, was president of the oil and gas-rich nation for three decades.
Former president Nazarbayev's daughter, Dr Dariga Nazarbayeva, married Rakhat Aliyev.
The opera-singing multi-lingual former business woman is now the chair of Kazakhstan's senate - and is tipped to possibly become president of Kazakhstan in the future.
Rakhat Aliyev, her ex-husband, was once a senior figure in the government.
However, he fell out with the president, split from his wife and was accused of major crimes - driving him into de facto exile.
In 2015 Rakhat Aliyev was found dead in an Austrian prison cell. He had apparently killed himself while awaiting trial for the alleged murder of two bankers in Kazakhstan.
Court papers show that the National Crime Agency suspects that Rakhat Aliyev and members of his family were involved in serious crime in Kazakhstan.
"I suspect that Rakhat Aliyev has been involved in... bribery, corruption, blackmail, conspiracy to defraud, forgery and money laundering," says a statement from an investigator.
"I also believe that members of his family - including Nurali Aliyev - have been involved in money laundering."
The NCA says the companies that own the properties in London are part of a pattern of "extreme secrecy" to hide assets.
What does the family say?
In statements on Tuesday morning, the mother and son said they wanted to swiftly clear their names and were frustrated with how the NCA had targeted them. They both say they had no contact with Rakhat after the family split.
Clare Montgomery QC, lawyer for some of the companies that own the properties, told the court that the NCA's case was "tissue thin".
She said Mrs Nazarbayeva had offered clearly to answer the NCA's questions by providing proof of her own independent finances and wealth - and the details of how her acrimonious and public split from her late husband showed she had nothing to do with his criminality.
She accused the NCA of "an absurdly patriarchal view of the world".
Instead, she argued, "there is a woman who is economically active throughout the period who might just have conceivably earned her own money."
The family and lawyers say they gave the NCA detailed evidence of how Dr Nazarbayeva managed her wealth and organised their ownership of homes in a tax efficient manner.
"The NCA has refused to engage with the material that has been provided," Ms Montgomery told the court.
"They insist that the application is made in court, in public, for reasons that do not reflect well on their ability to review the decisions they have made in this case."
The case continues on Wednesday.