Britain's biggest drug maker has told Sky News it rejects claims by Chinese authorities that it offered bribes to doctors and hospitals.
GlaxoSmithKline (GSK) had been accused by China's Public Security Bureau (PSB) of offering free travel as "large bribes".
It said the bribes were "to open new sales channels and increase drug revenues" and given to doctors, hospitals, foundations and medical associations.
In a statement to Sky News, GSK said: "We take all allegations of bribery and corruption seriously. We continuously monitor our businesses to ensure they meet our strict compliance procedures
"We have done this in China and found no evidence of bribery or corruption of doctors or government officials."
It added: "We are aware of the statement from the PSB. We are willing to co-operate with the authorities in this inquiry.
"But this is the first official communication GSK has received from the PSB in relation to the specific nature of its investigation."
The Chinese authorities allegedly identified employees only as "high officials" but gave no details of the size of payments or who received them.
The Chinese authorities said the investigation took place in Shanghai and the cities of Changsha and Zhengzhou.
"After questioning, the suspects confessed to the crime," the PSB statement said.
Sky sources confirmed that a British national was detained and questioned by Chinese authorities in Shanghai and has has now been released.
Sources revealed that dozens of Chinese police entered the GSK Shanghai offices on June 27, entered the offices of senior British staff and seized paperwork.
After the raid GSK circulated an internal memo which said: "At this stage, it is unclear about the precise nature/purpose of their visit and investigation.
"We will of course cooperate with their inquiries, but are unable to comment further at this stage."
It added: "Generally speaking, travel to China can continue as planned, unless you are planning to visit the GSK Pharmaceuticals offices to meet with senior management, in which case you should check with your host to ensure that the current meeting arrangements still stand."
A Foreign Office spokesman told Sky News: "We are aware of the Chinese investigation, and we are providing consular assistance to a British national.
"We are in contact with GSK and are in the process of seeking further information from the Chinese authorities."
Sky News Asia Correspondent Mark Stone, reporting from Beijing, said: "This comes a week after police in a city in south-central China said they were investigating high level Chinese staff."
Police in Changsha announced two weeks ago that GSK employees had been detained for questioning about unspecified "economic crimes".
Brentford-based GSK said in June that it had investigated an accusation that its salespeople in China bribed doctors and found no evidence of wrongdoing.
Last week Chinese state media reported that the government was investigating production costs for 60 foreign and domestic drug companies in a possible first step toward changing state-set maximum prices.
The announcement gave no indication any companies were suspected of wrongdoing.
:: In late Thursday trading in London shares in GSK remained virtually flat.