Macau casinos will formally ban ‘proxy betting’ starting on Monday, a move that could put further downward pressure on the city’s VIP gambling market.

Beijing’s corruption crackdown has convinced many wealthy Chinese that it’s unwise to be seen traveling to Macau. Some got around this restriction by enlisting a trusted proxy, who would sit at a Macau gaming table relaying real-time card info to the VIP on the mainland, who would advise how he wished to wager on a particular hand.

Macau regulators tolerated this activity provided there was no real-time video information transmitted from the VIP room. Not all Macau operators allowed the activity – particularly US companies who feared violating ‘know your customer’ regulatory guidelines back home – but analysts estimated proxy betting accounted for between 5% and 10% of Macau’s total VIP turnover.

On Thursday, Wynn Resorts boss Steve Wynn discussed the matter during his company’s Q1 earnings call. Referencing industry rumors re a proxy betting clampdown, Wynn said Macau regulators had “ended it. Okay, as of now it is illegal, there is no more phone betting. They stopped it today, the [Gaming Inspection Coordination Bureau, aka DICJ) made it official. It is finito.”