At least 18 more people have been detained in China in connection with a corruption scandal involving British drugmaker.
GlaxoSmithKline, state media reported, giving more details on an investigation that has rocked the company.
China's state radio reported late on Friday on its website that police in the central city of Zhengzhou had "recently held, in accordance with the law, 18 GlaxoSmithKline (China) employees and some medical personnel".
It provided no details of the detentions nor say exactly when they happened.
The Zhengzhou police news department, reached by telephone, said they were "unaware of the situation" and declined to comment further.
A GSK spokesman in London declined to comment on the report.
China's Ministry of Public Security said late on Friday GSK's former general manager for the country, Mark Reilly, currently in Britain, would return to China to cooperate in the investigation.
"The Ministry of Public Security welcomes GSK's position, and will provide necessary help to the work of the company's audit team, and hopes that GSK China's operations and production will return to normal as soon as possible," it said.
Chinese police had earlier announced the detention of four Chinese GSK executives in connection with allegations that the drugmaker funneled up to 3 billion yuan ($489 million) to travel agencies to facilitate bribes to doctors and officials.