Customs today announced it detected the largest-ever counterfeit face mask case on October 28, when it seized about 100,000 masks in a special operation.

The suspected counterfeit medical-grade face masks have an estimated market value of about $3 million and were intended to be transshipped overseas via Hong Kong, the department said, adding that one person was arrested in the operation.

The case is the largest-ever in terms of quantity and seizure value.

Customs earlier received information alleging that a company was suspected of selling counterfeit face masks.

After an investigation with the assistance of the trademark owner, officers seized the batch of masks at a storehouse in Yuen Long.

They further raided a trading company in connection with the case in San Po Kong and a residential premise in Kowloon City on the same day. A 71-year-old man in charge of the trading company was arrested.

Initial investigations revealed that unscrupulous merchants intended to transship the batch of masks overseas for sale and profit. Customs is investigating the source of the face masks involved in the case.

Samples have also been sent to a laboratory for safety testing.

Customs will continue to take stringent enforcement action and maintain close contact with trademark owners in monitoring the market situation to proactively combat counterfeit protective items.

Since January, the department has conducted spot checks and enforcement operations on common protective items in the city.

More than 6,000 officers have been mobilised to conduct over 38,000 inspections at retail spots.

Investigations have been conducted against 17 cases of suspected violations of the Trade Descriptions Ordinance and 13 cases of suspected violations of the Consumer Goods Safety Ordinance. Eighty people have been arrested so far.

Goods suspected of violating the law, including nearly 6 million surgical masks, 314 bottles of disinfectant alcohol and 23 bottles of normal saline, have been seized.

The public can report suspected violations by calling 2545 6182 or by sending email.