A Chinese national has been convicted of playing a key role in what is believed to be the single largest cryptocurrency seizure in the world, worth more than ?5bn ($6.7bn).

Zhimin Qian, also known as Yadi Zhang, pleaded guilty on Monday at Southwark Crown Court, London of illegally acquiring and possessing the cryptocurrency.

Between 2014 and 2017, she led a large-scale scam in China by cheating more than 128,000 victims and storing the stolen funds in Bitcoin assets, the Metropolitan Police said in a statement.

The Met said the 47-year-old's guilty plea follows a seven-year probe into a global money laundering web.

A total of 61,000 bitcoins were seized from Qian, the Met said.

The police said the probe began in 2018 after they got a tipoff about the transfer of criminal assets.

Qian had been "evading justice" for five years up to her arrest, which required a complex investigation involving multiple jurisdictions, said Detective Sergeant Isabella Grotto, who led the Met's investigation.

She fled China using false documents and entered the UK, where she attempted to launder the stolen money by buying property, said the Met.

Qian had help from a Chinese takeaway worker named Jian Wen, who was jailed for six years and eight months last year for her part in the criminal operation.

Wen, 44, laundered the proceeds from the scam and moved from living above a restaurant to a "multi-million pound rented house" in North London, said the Crown Prosecution Service (CPS) earlier this year.

She also bought two properties in Dubai worth more than ?500,000, the CPS said.

The Met said it seized more than ?300m worth of Bitcoin from Wen.

Wen claimed that she bought the properties for an employer from China. But the CPS said the large amount of bitcoin and lack of evidence of how she came by it indicated that it was from a criminal source.

Chinese media outlet Lifeweek reported in 2024 that investors, mostly between 50 and 75 years old, had poured "hundreds of thousands to tens of millions" of yuan into investments promoted by Qian.

The schemes capitalized on cryptocurrency's popularity in China at the time, promising daily dividends and guaranteed profits, according to Lifeweek.

Qian's company claimed it would help China become a hub for finance and technology and showed off projects and investments it said it had across the country.

Some of the victims - including business people, bank employees and members of the judiciary - were reportedly urged to invest with Qian's scheme by friends and family.

The investors reportedly knew little about Qian, who was described as "the goddess of wealth".

"Bitcoin and other cryptocurrencies are increasingly being used by organized criminals to disguise and transfer assets, so that fraudsters may enjoy the benefits of their criminal conduct," said deputy chief Crown prosecutor, Robin Weyell.

"This case, involving the largest cryptocurrency seizure in the UK, illustrates the scale of criminal proceeds available to those fraudsters."

Monday's conviction marks the "culmination of years of dedicated investigation", which has involved the police and Chinese law enforcement teams, said Will Lyne, the Met's Head of Economic and Cybercrime Command.

The Met said the investigation is still ongoing.

The CPS is working to ensure the fraudsters do not get hold of the stolen funds, the Met said. Many of the victims had some of their money returned to them by a compensation scheme established in China, the CPS said last year.

Qian is being held in custody ahead of sentencing. The date of her sentencing has yet to be fixed.

The BBC has contacted the Chinese embassy in the UK for comment. (BBC)

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