Beijing police have detained five people suspected of supplying fake alcohol to bars and seized more than 37,000 bottles of fake booze in a crackdown.

Authorities said they received a report from residents in September saying a man nicknamed Lao Tou allegedly led a gang suppling fake foreign alcohol on bar street in Sanlitun, the capital's Chaoyang district, according to Beijing Public Security Bureau.

After an investigation, the bureau dispatched 60 police officers to Chaoyang and Tongzhou districts on Dec 23, arresting 12 people and busting five gangs producing fake alcohol.

Five of the people detained said they bought or recycled high-class wine bottles and then put low-quality alcohol in them. They then sold the bottles to bars in Sanlitun, police said.

As the Spring Festival approaches, the number of foreign wine and beer brands in China has been increasing, aiming to satisfy residents’ demand. But that has also increased the amount of fake alcohol in the market, police said.

To curb such illegal sales and provide residents with a clean market, police have developed a 50-day campaign since December and the crackdown was part of those efforts.

Under the current Criminal Law, those who produce and sell fake foreign alcohol could face fines and up to seven years in jail.