More than GBP 4 million in the cryptocurrency has been returned to 23 people who have been victims of fraudulent trade fraud.
Greater Manchester Police (GMP) seized Ethereum and additional cash worth more than GBP 16 million in July 2021.
A man and a woman between the ages of 23 and 25 were arrested on suspicion of fraud and money laundering and were later released and investigated.
The force said it was working to return the remaining money to another 127 victims of the fraud.
A GMP spokesman said 150 people based in the UK, US, Europe, China, Australia and Hong Kong had invested money in what they thought was an online savings and trading service. He said supporters of the service waited until a large amount was paid, and then closed the site and transferred the funds to their accounts.
Officers received information that the perpetrators were in Manchester and carried out attacks.
An encrypted USB key with stolen Ethere, worth £ 7 million, the world’s second largest cryptocurrency after bitcoin, was seized, while another £ 9 million of cryptocurrency lay in an “online safe” a few days ago, a spokesman said.
Det Ch Insp Joe Harrop encouraged anyone who believes the target of fraud to speak up, saying that trading money online “is not very technical and requires thorough knowledge to make sure your money is safe.”
“If that sounds too good to be true, maybe it is,” he said.