Advertising giant WPP says it has fired an executive detained in China on suspicion of bribery.

Last week, news emerged that the Chinese police had raided the Shanghai office of advertising agency GroupM, owned by WPP.

On Tuesday, the British firm told CNN that "we are cooperating with the authorities and conducting our own investigation with an independent third party."

"We are terminating the executive's employment with the company, and GroupM is suspending trade with any external organization we understand to be part of the police inquiries," WPP (WPP) said in a statement.

The world's biggest ad agency declined to provide further details of the case, citing an active police investigation.

On Saturday, Shanghai police said in a statement that it had detained a senior executive of an advertising agency along with two others. Based on a preliminary investigation, they were suspected of taking bribes from 2019 to February 2023, police said. The police didn't name the company, but the Financial Times and Chinese state media linked it to GroupM.

The news came shortly after Japanese officials revealed last week that China had arrested a Japanese national who reportedly worked for drugmaker Astellas Pharma. The person had been detained previously on suspicion of violating the country's criminal law and anti-espionage law.

On Sunday, Chinese state media reported that Foxconn, the Taiwanese electronics manufacturer, was also under investigation by authorities in China over land use and tax concerns.

Weeks earlier, Foxconn founder Terry Gou had announced his bid for Taiwan's presidency and told the public that he wouldn't be pressured to follow orders from Beijing, despite his long-running business ties to the country.

While it is unclear whether the investigations are connected to Gou's political ambitions, experts have warned the developments may further rattle foreign businesses in China.

In July, China broadened the scope of its already sweeping counter-espionage law in a move that analysts warned could create further legal risks or uncertainty for foreign businesses, as well as journalists and academics.

That same month, China fined Mintz Group, a US corporate due diligence firm, about $1.5 million for allegedly conducting unapproved statistical work in the country. Officials had earlier closed the group's Beijing office in March and detained five of its local employees.

In May, state security authorities said they had raided several offices of Capvision, an advisory network. The announcement came a month after police questioned employees at the Shanghai office of top consultancy Bain.