The French offices of Chinese telecoms giant Huawei were raided this week on suspicion of improper behaviour, a judicial source told AFP on Thursday.
The source said Tuesday's raids were carried out as part of a preliminary investigation launched by France's financial prosecution service (PNF).
No other details were immediately available about the probe into the company, whose French offices are located just outside Paris in Boulogne-Billancourt. In a statement, Huawei France denied wrongdoing.
"Huawei has fully cooperated with investigators and will continue to do so," the company said.
"Huawei has been present in France for more than 20 years and has always respected all French laws and regulations."
The company added it was "confident" about the conclusions of the probe. Improper behaviour can include offences such as corruption and influence peddling. Huawei arrived in France in 2003 and now runs six research centres and a global design centre in the country.
The telecoms giant is currently building a factory in Alsace in northeaster France, its first outside China, to produce equipment for mobile telecom networks, in particular 5G.
Huawei has around 20 per cent of France's telecommunications market. Founded in 1987, Huawei is the world's leading equipment manufacturer for 5G, the fifth generation of mobile internet.
The Shenzhen-based giant has been at the centre of an intense standoff between China and the United States, with Washington warning its equipment could be used for state espionage, an allegation the company denies.
In June last year, the European Commission warned that Huawei and another Chinese telecoms giant, ZTE, pose a risk to the EU's security.
The EU's internal market commissioner, Thierry Breton, has called on the bloc's 27 member states and its telecoms operators to exclude Huawei and ZTE equipment from their mobile networks.
