A government spokeswoman said at the time it hoped the ruling would be a deterrent, adding they would continue to take enforcement action against any unlawful ride-sharing operations.

In a statement released on Tuesday, Uber Hong Kong said it was “extremely disappointed” by the police action. “We stand together with the driver partners and their families, and will continue to provide assistance, including legal support, during this difficult time,” it said.

“Ridesharing should not be a crime. Hong Kong is an international city known for its embrace of global economic trends and new technologies, but current transportation regulations have failed to keep up with innovation,” it said.

The firm added it hoped to work with Hong Kong authorities, especially the new administration, in resolving the issue with Uber drivers and riders.

Uber Hong Kong, founded in mid-2014, has so far served one million riders in the city using more than 30,000 drivers with 80 per cent of them working as part-timers.

Another police source said it was not known whether the third-party insurance coverage Uber drivers purchased met the requirements.

But he insisted that it was “illegal” to provide such a car-hailing service without a car hire permit.

Over the past three weeks, police officers posing as customers were deployed to take trips around the city using the Uber car-hailing app. The officers paid by credit card for the fares through the app.

After gathering evidence, officers swooped into action on Tuesday, raiding a number of locations. During the operation a total of 22 drivers – 21 men and one woman – were picked up and 12 vehicles impounded.

Twelve of the 22 drivers were understood to have been caught when they arrived to pick up undercover police officers in Kowloon Tong and Tseung Kwan O.

Chief Inspector Edwin Lau Tat-fai of the Kowloon West traffic unit said police believed the drivers had not applied for a hire car permit from the Transport Department, and did not have valid third-party insurance for hire car services.

“Initial investigations showed the drivers had been with the service for periods ranging from several days to several years and had charged clients between HK$50 and HK$150 per trip,” he said.

Lau confirmed the operation had targeted one ride-hailing app in particular but refused to reveal the name of the operator. He said police would continue to launch enforcement action against such illegal services.

Police sources, however, said the target of the operation had been Uber drivers.

The chief inspector warned that “anyone involved in aiding and abetting others to commit offences may hold the relevant legal responsibility”.

But he added that those arrested were likely to be freed on bail pending further investigations.

Democratic Party lawmaker Andrew Wan Siu-kin criticised the police action and the government for failing to address the problem by allowing Uber to operate legally and making the drivers “scapegoats”.

Saying that existing laws were lagging behind the e-commerce trend, he said there was demand for the Uber service as the current taxi service was not up to standard.

He said the government should review existing laws as early as possible to let Uber services operate legally in the city.

Under the Road Traffic Ordinance, anyone using a motor vehicle for the carriage of passengers for hire or reward must obtain a hire car permit.

Driving without valid third-party insurance is a breach of the Motor Vehicles Insurance (Third Party Risks) Ordinance.