The Beijing health authority held talks with all third-party nucleic acid testing companies in the city on Friday after illegal behaviors involving the tests were reported recently. A city-wide on-site examination of all testing institutions will be conducted, a senior official said at a news conference on Friday afternoon.

"Beijing has done several rounds of mass nucleic acid tests in most districts since the outbreak occurred on April 22," said Li Ang, deputy director of the Beijing Health Commission. "Testing labs and institutions at all levels - including national public labs, city and district level testing bases, as well as third-party institutions, have completed several rounds of testing, which have provided data basis for measures we have taken to control the virus' spread."

However, during recent supervision and checks, some testing institutions were found to have engaged in illegal behavior, which has influenced testing quality and the effect of epidemic control and prevention work, he said.

Beijing police reported a testing lab named Jinzhun Medical, which has diluted samples and put multiple tubes together during tests.

"The wrongdoing of the company has affected the accuracy of the testing results," said Pan Xuhong, spokesman for Beijing's public security bureau on Friday. "The bureau has filed a case against the company for obstructing the prevention and control of infectious diseases."

The police has taken criminal coercive measures against 17 people involved, including the legal representative surnamed Wang (male, 43). The case is under further investigation.

Yang Daqing, deputy director of the Fangshan district health commission, together with two subordinates -- Jin Changhao and Xing Man, are under investigation, due to alleged serious violation of discipline and law, according to an announcement from the Beijing authority for discipline inspection on Friday.

The announcement said they are related to the case of Beijing Pushi Medical Laboratory Co, which was reported to have provided test result data that was lower than the number of samples collected.

Last week, the Beijing police took measures against six people related to the lab whose business licenses got revoked. The authority has filed a case for obstructing the prevention and control of infectious diseases.

"The government will severely punish testing labs which affect the accuracy of the results to obtaining profit illegally," Xu Hejian, spokesman of the city government, said on Friday.