A French-Syrian man has been detained by French police on suspicion of supplying components for the manufacture of through his shipping company, sources briefed on the case told AFP Sunday.
The man, who was born in 1962 and lives abroad, was arrested Saturday in the south of according to one of the sources.
"He returned to France with his family for the holidays," a source close to the case told AFP.
He has been held on suspicion of "conspiracy to commit crimes against humanity, accessory to crimes against humanity and accessory to war crimes," a judicial source told AFP.
The alleged crimes date back to March 2011, the start of the civil war in Syria and continued until at least January 2018, possibly later, said the source.
"This man is accused of having, through a company based in different places, in France and in the United Arab Emirates, participated in supplying the means to various state structures of the Syrian regime in charge of the production of non-conventional weapons."
According to one legal source, it is the first time someone has been placed under formal investigation in France on suspicion of supporting the Syrian army.
The war in Syria has killed close to half a million people and spurred the largest conflict-induced displacement since World War II.
Syria denies the use of chemical weapons. It insists it handed over its weapons stockpiles under a 2013 agreement with the United States and Russia, prompted by a suspected sarin gas attack that killed 1,400 in the Damascus suburb of Ghouta.
But Syria was stripped of its Organisation for the Prohibition of Chemical Weapons (OPCW) voting rights in April after a probe blamed it for further poison gas attacks.
It will remain suspended until it has fully declared its chemical weapons and weapons-making facilities.