UK Treasuryโs Office of Financial Sanctions Implementation updated its sanctions guidance on 30 August to explicitly include โcryptoassetsโ among those that must be frozen if sanctions are imposed on a person or company.
Crypto exchanges must report suspected sanctions breaches to UK authorities. If they fail to report clients designated for sanctions, they would be committing a criminal offence.
For more information see UK forces crypto exchanges to report suspected sanction breaches