(IDEX Online) - Customs officers in Hong Kong have arrested four people in a crackdown on crime syndicate suspected of laundering money through $64m of bogus diamond transactions.They say it's the first-ever money laundering case they've ever smashed that had centered on "transnational diamond trading".Their investigation revealed that members of a crime syndicate had established diamond trading companies in both Hong Kong and India. They are suspected of having exported synthetic diamonds of low value from Hong Kong to India, but lodged a false declaration as natural diamonds of high value, in a bid to reasonably transfer significant amounts of suspicious funds from India to Hong Kong.Customs raided four residential premises and four commercial units across Hong Kong on 19 and 20 December.They froze assets worth just over $1m held by the four people arrested - described as "one Chinese male and three non-ethnic Chinese males".Hong Kong Customs said in a statement today (28 December) that it "mounted an operation codenamed Gem Crusher between December 19 and 20 and successfully smashed a large-scale transnational money laundering syndicate that had laundered about HKD500m (US$64m)."It was the first-ever money laundering case using transnational diamond trading detected by Customs."