First used at a private club in Kingston Jamaica, where gambling was banned but condoned by high Jamacian officials for visiting dignataries. The chips then turned up in anj illegal game somewhere in New York City. The game was busted the chips seized by the police and I was told they were dumped in the East River.
Please note I find it hard to believe that the police would dump the chips in the East River unless it was to destry evidence before the trial.
The other option is that the game operators dumped the chips to keep them out of the hands of the police.