An Iranian national based in Spain is suing a fintech firm in the High Court over the company’s alleged seizure of his $2.8 million (€2.4 million) in cryptocurrency assets.

Ali Asghar Afrouz (74) claims Coinbase wrongfully froze and seized his assets held in his account on the platform following purported concerns about the source of his wealth.

In court documents, Afrouz submits Coinbase told him his assets were seized by US authorities following the execution of a warrant. He asserts that there are no grounds for the seizure of his assets by the US.

Afrouz, with an address in Marbella, Spain, is suing Coinbase Europe Ltd and Coinbase Luxembourg SA, seeking the return of his assets.

Coinbase Europe’s parent company, Coinbase Group, is the largest cryptocurrency exchange in the US and the world’s biggest custodian of Bitcoin. Coinbase Europe is regulated by the Central Bank of Ireland.