Vietnam’s lottery market is heating up after operators accused the country’s newest and flashiest lottery of engaging in illegal anti-competitive practices.

On Monday, VNexpress reported that the Southern Lottery Council, an organization representing 21 small Vietnamese lotteries, had formally asked the Ministry of Finance to investigate rival Vietlott for allegedly engaging in “illegal operations.” All Vietnamese lotteries are state-owned.

In July, Vietlott launched its new Western-style Mega 6/45 game in partnership with Malaysian conglomerate Berjaya. Traditional Vietnamese pre-printed ticket lotteries cap jackpots at VND 1.5b (US $67k) but 6/45’s main prize offered a VND 12b payday as well as the possibility of much higher prizes when the draws failed to produce a grand prize winner.

In October, a 6/45 winner claimed a record VND 92b jackpot after the main prize was rolled over 39 times. While most observers expected sales to drop for a period once the bubble had burst, Vietlott awarded a VND 65b prize just two weeks later, further boosting the new lottery’s profile among players.