The move comes after police arrested the four individuals at the weekend in the southwestern Gironde region where the two Chinese suspects allegedly rented an Airbnb as part of a plan to capture sensitive information, including military intelligence.

The Paris prosecutor's office said two individuals have been remanded into custody and two others placed under judicial supervision, without offering details on their identities.

The probe focuses on the "delivery of information to a foreign power" likely to harm key national interests. This is punishable by up to 15 years behind bars.

The case was triggered after residents on January 30 spotted the installation of a satellite dish approximately two metres (around six-and-a-half feet) in diameter, which coincided with a local internet outage.

A search conducted the following day led to the discovery of "a system of computers connected to satellite dishes enabling the capture of satellite data", according to the prosecutor's office.

The set-up made it possible to intercept "exchanges between military entities", it said.

The two Chinese nationals had allegedly travelled to France with the intent to capture data from the Starlink satellite internet system and other "entities of vital importance" and transmit it back to China.

Their visa applications stated that they worked as engineers for a research and development company specialising in wireless communication equipment.

The two other suspects were arrested over allegations they illegally imported the equipment, the prosecutor's office said, without adding details of their identities.

In a separate case, a French applied mathematics professor was in December charged with allowing a Chinese delegation to visit sensitive sites in a case of suspected espionage. The engineering institute where he works has been partially designated as a "restricted area" since 2019.