HAIKOU -- A chain pharmacy in South China's Hainan province was fined 3 million yuan (about $430,000) for hiking the prices of masks amid the novel coronavirus outbreak, local authorities said Thursday.

The Hainan Yijiutang Pharmaceutical Company in Wenchang city with its 28 drugstores has increased the prices of masks up to over four times since Jan. 21, said the provincial market regulator.

Despite a warning from the market regulator, the company did not stop the price-gouging but instead resorted to illegal practices such as forging the sales record so as to dodge the supervision.

An administrative penalty notice has been issued to the pharmaceutical company.

The Hainan provincial regulators of all levels have stepped up the supervision on prices of epidemic control materials since the outbreak of the epidemic. A total of 61 cases of price irregularities have been dealt with by Wednesday.