France, Sept. 18 -- The 35-year-old officer, who was serving in the Yvelines department west of Paris, was arrested by anti-terrorism investigators on 23 August as he left work.

He is suspected of planning violent attacks against state interests and of manufacturing weapons using a 3D printer, according to French broadcaster TF1/LCI, which revealed the case on Thursday.

A judicial source confirmed to French news agency AFP that the officer was accused of preparing a terrorist act as well as manufacturing weapons and committing a series of related offences.

A separate source close to the investigation described him as adhering to "a violent, radical, far-right ideology".

After spending 96 hours in police custody, the officer was formal...