Wanted: $6 million in missing gaming chips. Last seen: The lavish Wynn casino in Macau.

Police are hunting for millions of dollars in casino chips after they were stolen -- allegedly by one of Wynn's own croupiers -- raising security concerns in the world's biggest gambling hub.

The heist happened Tuesday at the Wynn Macau (WYNMF), one of the marquee destinations in a Chinese territory whose gambling revenues dwarf those of Las Vegas.

Macau police told CNNMoney that a dealer at the Wynn Macau and a potential accomplice have been arrested and that they are not currently looking for other suspects. They declined to identify the two people by name.

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Police didn't say how the stolen chips were taken past casino security. But local media reported that the suspect allegedly stuffed them into a bag in a VIP room and simply carried them out.

To turn the chips into hard cash, the thieves or their associates would eventually need to bring them back into the casino.

Wynn Macau is controlled by Wynn Resorts (WYNN), the Las Vegas casino firm founded by billionaire mogul Steve Wynn. Wynn Macau didn't respond to requests for comment Friday.

Casino operators could face pressure from authorities to tighten up oversight of gaming rooms following the theft, according to Vitaly Umansky, an analyst at investment firm Sanford Bernstein.

Rules around gambling in Macau are more relaxed than in Las Vegas, he said. Most of the high-stakes action in Macau takes place in so-called VIP rooms, which aren't run by the casinos themselves but by separate junket operators from mainland China.

That makes it difficult for casinos to manage exactly what goes on inside.

"The junkets get a lot of leeway inside the rooms in terms of how money changes hands and how chips change hands. That's something that may need to get evaluated," Umansky said.

Big heists in the city's casinos are rare, but they do happen. In 2015, a junket operator said it had been scammed out of more than $30 million. That incident also happened at a Wynn casino.

Related: China jails top casino exec over gambling crimes

Gambling is a big business in Macau, a former Portuguese colony.

The city's revenues from games like baccarat and blackjack are about five times bigger than those generated on the Las Vegas strip.

Macau's casinos raked in just over $33 billion last year, an increase of about 20% from the year before.

That snapped a multi-year losing streak for the gambling industry in the city. Macau is popular with visitors from mainland China, where gambling is illegal.

Revenues began falling in 2014, hurt by a far-reaching crackdown on corruption by Chinese President Xi Jinping. That deterred some big spenders from visiting Macau's VIP rooms.

-- Qiaoqiao Yu contributed to this report.