UK Man Claims Estranged Wife Lifted $172M in Bitcoin After Filming His Seed Phrase

A UK High Court dispute lays bare the real weak point in self-custody: not cryptography, but people. Court filings allege that a husband’s now-estranged wife covertly filmed him entering his seed phrase and then drained roughly $172 million in Bitcoin. The legal record is unusually detailed—and it reads like a case study in how domestic surveillance can defeat even well-chosen hardware wallets.

According to the claim, UK resident Ping Fai Yuen held 2,323 BTC on a Trezor in 2023. On August 2 of that year, 2,323 BTC left his wallet and, after a series of moves, was split across 71 Bitcoin addresses. No further movements have been observed since December 21, 2023.

The filings say Yuen’s daughter warned him in July that his wife, Fun Yung Li, was attempting to take his Bitcoin. Yuen then installed audio equipment at home. Recordings from July 29, 2023 allegedly capture Fun discussing CCTV set up in the house to observe where he sat and concealed the password for the wallet. The claim asserts she—and possibly her sister, Lai Yung Li, named as a second defendant—secretly recorded him to extract the seed phrase. Excerpts in the court papers indicate statements that the Bitcoin had been transferred to her and an intention to take the entire amount.

When Yuen saw his Bitcoin had moved, he confronted Fun and assaulted her. He was arrested and later pleaded guilty to assault occasioning actual bodily harm and two counts of common assault. He also reported the crypto theft, prompting police to arrest Fun in 2023 and seize 10 cold wallets, at least three labeled in ways attributable to Yuen. After a no-comment interview, she was released on bail. Police have since indicated they will take no further action absent new evidence.

In November 2025, Yuen sought a proprietary asset preservation injunction. He asked the court to declare him the owner of the 2,323 BTC, freeze Fun’s crypto assets, and compel the return of the Bitcoin—or the equivalent value in British pounds. Following a March 2 hearing, Justice Cotter wrote that the claimant has a very high probability of success, citing prior warnings to Yuen about Fun’s intentions, transcripts he described as damning, and the discovery of equipment capable of exfiltrating the Bitcoin. He emphasized a preference for the simplest explanation and noted Fun has had an opportunity to provide her own account but has chosen not to. Given Bitcoin’s volatility, he urged an early trial.

What matters here is not that a Trezor was involved—properly used, hardware wallets are robust—but that the operational perimeter around the seed phrase collapsed. Anyone who treats seed phrases like passwords underestimates how potent modern cameras and microphones are in close quarters. A fixed security camera with a decent angle can capture hand movements, keystrokes, or the order of words on a slip of paper; a phone on a shelf can pick up clicks or spoken confirmations; a partner who knows your routines can wait for the weakest moment.

This is why sophisticated holders often separate knowledge and control. Multisig with geographically and personally segregated keys, passphrases distinct from the 24-word mnemonic, Shamir backups with split thresholds, and decoy wallets for duress—all of these are designed to raise the cost of compromise from a single successful recording to a coordinated, multi-location breach. Even a simple change, like never revealing the seed in a domestic setting and using a passphrase memorized rather than written, meaningfully shifts the attack surface.

The legal angle is just as instructive. Crypto’s immutability does not negate property rights; courts can and do issue proprietary injunctions, freeze accounts, and recognize on-chain assets as recoverable property. Yet enforcement remains tethered to identification and custody: you can freeze what you can find and what a defendant or intermediary controls. Here, dispersion across 71 addresses with no movement since December 2023 suggests either deliberate dormancy or a wait-for-heat-to-die strategy. An early trial, as the judge notes, reduces the risk that favorable adjudication arrives after another price swing complicates restitution.

People tend to over-index on exotic hacks and underweight the mundane: cameras in kitchens, whispered seed phrases, routine complacency. This case spotlights how domestic proximity can become the ultimate side channel—and how combining strong cryptography with disciplined, boring process is still the only durable defense.