A former procurement manager at one of Hong Kong's best-known jewelry retailers pleaded guilty in the High Court on Monday to stealing diamonds worth more than HK$11 million (US$1.4 million) from the company's suppliers over a six-year period, a scheme he told the court was driven by a gambling addiction. Mui Ka-fai, 63, entered guilty pleas to three counts of theft covering offenses committed between 2017 and 2023 while he was employed by Tse Sui Luen Jewellery, a major player in the city's gold and diamond trade 1. The case has drawn attention to the internal controls governing consignment arrangements between jewelers and their suppliers, a cornerstone of the industry's supply chain.
According to the prosecution's summary read in court, Mui exploited his position as a diamond buyer to obtain small stones from the jeweller's regular suppliers on consignment. Rather than returning unsold inventory or accounting for it properly, he manipulated the consignment records to conceal the diversion of goods, then resold the diamonds once or twice a month for personal profit 1. The scheme persisted for six years, suggesting that the falsified paperwork went undetected through multiple audit cycles and inventory reconciliations. The total value of the stolen gems exceeded HK$11 million, a figure that reflects both the volume of stones moved and the markup achievable in the secondary market for small diamonds.
Tse Sui Luen Jewellery, founded in 1971, operates a network of retail outlets across Hong Kong and mainland China and is a significant buyer in the global diamond supply chain. Like many jewelers, it relies on consignment arrangements with diamond dealers and sightholders, under which stones are delivered for inspection and potential purchase, with title passing only upon sale or explicit acceptance. These arrangements depend heavily on trust and accurate record-keeping, since the supplier retains ownership until the transaction is finalized. Mui's role as procurement manager placed him at the nexus of this process, giving him both the access and the authority to alter the documentation that tracked which stones had been returned, sold, or remained on memo.
The court heard that Mui told investigators he used the proceeds to fund a gambling habit, a detail that aligns with a pattern seen in other high-value occupational fraud cases in Hong Kong. The city's proximity to Macau's casino resorts and the prevalence of both legal and underground betting options have long been cited by criminologists as a factor in white-collar crime involving finance, logistics, and luxury-goods employees. While the judgment did not specify the venues or forms of gambling involved, the defendant's admission underscores how personal financial pressure can subvert even long-standing employees in positions of trust. Mui had been with the company long enough to understand its control environment and to identify the gaps that allowed the consignment records to be altered without immediate detection.
The three theft charges to which Mui pleaded guilty likely correspond to distinct phases or tranches of the scheme, each representing a course of conduct rather than a single act. Prosecutors often structure charges this way when a defendant engages in a continuing pattern of misappropriation, allowing the court to consider the full scope of the offending at sentencing. The High Court will now set a date for sentencing, at which point the defense is expected to present mitigation evidence, potentially including psychiatric assessments related to the gambling addiction. Restitution will also be a central issue; Tse Sui Luen and its suppliers will seek recovery of the stolen goods or their value, though much of the proceeds may have been lost to gambling.
Beyond the immediate parties, the case raises questions about the adequacy of verification procedures in the diamond consignment pipeline. Industry participants typically rely on a combination of physical audits, digital tracking systems, and reconciliation of supplier statements to detect discrepancies. That a six-year scheme involving monthly diversions could persist suggests either that the controls were insufficiently rigorous or that Mui's familiarity with them allowed him to exploit blind spots. The Jewellers' and Goldsmiths' Association of Hong Kong has in recent years promoted tighter chain-of-custody standards, partly in response to anti-money-laundering obligations, but adoption varies across firms of different sizes.
For Tse Sui Luen, the reputational impact may be as consequential as the financial loss. The company's brand rests on consumer confidence in the authenticity and ethical sourcing of its merchandise. A high-profile internal theft, especially one involving manipulation of supplier relationships, could prompt counterparties to demand stricter contractual safeguards or more frequent independent audits. Suppliers, too, may reassess the credit and consignment terms they extend, potentially tightening the working-capital dynamics that allow smaller jewelers to maintain inventory without upfront payment.
The case also illustrates the intersection of addiction and occupational crime in a jurisdiction where gambling is culturally embedded yet legally constrained. Hong Kong's Gambling Ordinance permits only the Hong Kong Jockey Club to operate legal betting, but cross-border access to Macau and the proliferation of online platforms create avenues that are difficult to monitor. Employers in high-trust roles — procurement, treasury, logistics — have increasingly turned to background checks, periodic financial-health declarations, and whistleblower hotlines as preventive measures. Whether such measures would have detected Mui's conduct earlier remains an open question, given that his scheme relied on document manipulation rather than lifestyle changes that might trigger suspicion.
As the court prepares for sentencing, the outcome will be watched by compliance officers across the jewelry sector and by regulators focused on the integrity of high-value supply chains. The prosecution has signaled that the scale and duration of the offending, combined with the breach of fiduciary duty, warrant a substantial custodial sentence. For Mui, the guilty plea avoids a trial but does not eliminate the prospect of a lengthy prison term. For the industry, the episode serves as a reminder that the most valuable assets in the diamond trade are not the stones themselves but the systems of verification that allow them to move securely from mine to market.