The Immigration Department said on Thursday that 10 people, including eight illegal workers, have been arrested in a targeted operation against unlicensed photography and makeup services in Hong Kong.

The investigation began after officers, during routine online patrols, noticed a trend of mainland-based photographers and makeup artists advertising their services on social media, offering sessions in Hong Kong at significantly lower prices to attract local clients.

Between August 20 and 21, and September 2 and 3, undercover officers posed as customers to make bookings with the targeted group, who were arrested upon their arrival in Hong Kong.

Deputy commander (task force) Chun Yuk-tung said the eight illegal workers from the mainland consisted of one man and seven women aged 19 to 39. Four were photographers and the rest were makeup artists.

He said two Hong Kong residents were also arrested for allegedly collaborating with the illegal workers to aid and abet a breach of conditions of stay.

"Investigations revealed that the arrested mainland photographers charged between HK$300 and HK$2,000 per session, primarily for outdoor photography at popular spots like theme parks and waterfront parks," Chun said.

"Some photographers promoted themselves by saying they had purchased annual theme park passes to accompany customers into these venues for photography services.

"The arrested mainland makeup artists charged as low as HK$80 per session, with some renting local hotel rooms as temporary makeup studios for their clients, including those hosting weddings or attending large events."

Chun said seven of the illegal workers have been charged with violating their conditions of stay, of which five have already been sentenced to two months in prison.

He said officers seized photography equipment, props, makeup supplies and smartphones during the arrest, and that further arrests may follow.