Gambling technology provider Playtech saw its share price plunge by more than one-fifth on Thursday after the company issued a warning regarding its black-market Asian operations.

On Thursday, Playtech issued an update on its trading to date in H2, during which the gaming division’s daily average revenue “accelerated” and is “currently higher” than the average reported in the company’s interim results.

However, the company also warned that it had suffered “an impact from recent changing market conditions in certain parts of Asia.” Playtech said that while it had expected that activity at its Asian-facing licensees “would return to normalized levels in a relatively short timeframe, we are now not expecting any significant improvement in 2017.”

This impact is believed to be related to Playtech licensees’ significant online gambling operations in Malaysia. In September, Malaysian authorities announced their intention to “wipe out illegal gambling once and for all,” with a particular focus on stamping out online gambling.