How a Seed Phrase Leak Led to a $176M Bitcoin Theft Case

Code is not the weakest point in crypto thefts

In crypto, security is usually regarded as a technical issue. You are asked to safeguard your private keys, rely on a hardware wallet and steer clear of phishing links. Yet a prominent case in the UK reveals that the real vulnerability in this case might have had nothing to do with code.

The UK High Court is currently reviewing a case involving the alleged theft of 2,323 Bitcoin (BTC), worth about $176 million. The theft did not stem from hacking or malware. Instead, it began with a seed phrase being exposed, which became the single point of failure in self-custody.

The dispute centers on Ping Fai Yuen, who claims that his estranged wife, Fun Yung Li, and her sister gained access to his Bitcoin by secretly recording his wallet’s recovery information.

The assets were held in a hardware wallet, designed to keep private keys completely offline and shielded from remote threats. Yet the theft still happened and it required no breach of encryption.

Court documents suggest the theft only required discovering the seed phrase.

Alleged timeline of the crypto theft

The allegations describe events that suggest surveillance rather than digital intrusion.

The individuals in question are accused of using a camera or recording device to capture the seed phrase and related codes.

The claimant later learned of the scheme after receiving a warning from his daughter.

He then set up audio recording equipment, which he says captured conversations about moving the funds.

The Bitcoin was subsequently transferred to 71 separate wallet addresses.

No additional movements have appeared on the blockchain since Dec. 21, 2023, indicating that the assets have remained inactive since the reported transfer.

Authorities are said to have confiscated devices and cold wallets as part of the inquiry, although the proceedings are still ongoing.

Did you know? In several past cases, hidden cameras, not hackers, have been the weakest link in crypto security. Physical surveillance has quietly become one of the most underestimated threats to self-custodied digital assets.