Fake luxury-branded cosmetics worth $120m have been seized in China.

The haul came after seven underground dens were raided earlier this month in the eastern city of Taizhou, revealing a stash of more than 1,200 boxes filled with counterfeit makeup featuring the labels Chanel, Christian Dior, L'Oréal SA's Lancôme and Estée Lauder.

Chinese media reported that 15 people have been arrested, of which 13 have been charged.

The fakes came to light following reports early last year that bogus products bearing the US health and beauty brand Amway were being sold online, which lead to an investigation by police.

Last year, the police raided a warehouse storing the spurious online store's merchandise and turned up 100 boxes of fake Amway products worth almost $30,000. The sting had a domino effect leading to the identification of other counterfeit operations.

One man is said to have admitted his role in running the racket of underground workshops, where raw materials were bought online and then mixed to make the beauty products. The packaging, which was purchased further south in Guangdong province, had QR codes copied from the genuine products.

The fake cosmetics, which were distributed throughout China, were sold online at 10 times the production cost and any complaints were dealt with by refunds in the hope police would not be notified.

This is not the first time Chinese conmen have been found producing fake beauty concoctions. In 2012, police seized more than $3m-worth of fake cosmetics that included batches of counterfeit Botox.

A report in 2015, noted that there were 56 raids in the Guangdong province alone confiscating fake beauty products worth $11m. The report said that counterfeit cosmetic operations required just a filling machine, a sealer and at most two workers. It said there were cases where licensed manufacturers were bribed for the anti-counterfeiting packaging designs.

A UK Intellectual Property Office report, published in 2012, said there was an increasing number of cases involving counterfeit cosmetics, with the finger pointed at operations coming out of China.

Meanwhile, earlier this week, Hong Kong cosmetics chain Colourmix was fined more than $20,000 for possessing 481 bottles of fake makeup remover labelled with the Bioderma brand. The counterfeits were found during a police raid in 2015 and featured spelling mistakes, misprints and incorrect expiry dates. A magistrate described Colourmix's quality assurance system as "seriously lacking" and "failing to achieve even the basic gatekeeping".