Hong Kong's leader on Friday said China would help authorities offer free coronavirus tests to residents as infections continue to rise in a finance hub where a deep distrust of Beijing has become embedded.

Initially, a poster child for the battle against the coronavirus, Hong Kong has seen a third wave brought in by certain business and logistic arrivals that were exempted from the compulsory quarantine rules. More than 2,500 new infections have been detected since the start of July -- nearly 70 percent of the total since the virus first hit the city in late January, and deaths have risen to 46.

City leader Carrie Lam said the government would introduce a free voluntary testing scheme in two weeks' time with support from medical officials from the Chinese mainland. "We want to do it as soon as possible within short duration, because the earlier that we could identify these silent transmitters, the better," Lam said.

The testing will be conducted by Hong Kong subsidiaries of three mainland companies including Chinese genomics firm BGI Group, she added. In other places around the world, residents would likely welcome a sudden increase in virus testing.

But many Hong Kongers remain deeply suspicious of Beijing as it stamps down on political freedoms, including imposing a sweeping new security law on the city last month. Biometric surveillance, including DNA, forms a core part of the authoritarian mainland's vast surveillance state.

Hong Kong opposition figures have expressed fears virus testing by mainland officials could help Beijing harvest DNA of Hong Kong's 7.5 million inhabitants. The Hong Kong government have dismissed those suggestions as unfounded rumours. 

During Friday's announcement Lam said testing laboratories would not be given any personal information and would not be able to collect DNA samples.

"If people still have concerns, they don't need to come forward," she said. "This is an entirely voluntary programme to provide testing for those who want to have a test."

She added that "conspiracy theories" were "damaging the relationship between the central government and Hong Kong".

The National Health Commission of China has sent an "advance unit" of clinical laboratory staff in the city on Sunday. Lam said another team has been set up to assist in building Hong Kong a makeshift hospital similar to those erected when the virus first emerged in the central Chinese city of Wuhan. 

Authorities recently opened a 500-bed temporary facility to treat non-serious infections in an exhibition centre near the airport and are expecting to boost its capacity by adding 1,400 beds. The new temporary hospital will be built nearby.