Magistrates have opened a probe after a French international rugby player posted a video in which he said he wanted to attack Arabs, the Paris prosecutor's office said on Tuesday.
Full-back Melvyn Jaminet, 25, was kicked off the squad earlier this month for the remarks in an Instagram story that was then deleted.
"I promise, the first Arab I see on the road, I'll headbutt him," Jaminet is filmed as saying in the video posted after France beat Argentina in a July 6 test match in the Latin American country.
Anti-racism NGO SOS Racisme filed a complaint and the investigation was opened on July 9 over an alleged "death threat due to origin", the prosecutor's office said.
The French Rugby Federation on July 7 called Jaminet's comment's "totally unacceptable" and said it would conduct an internal investigation as it removed him from the team.
Its president Florian Grill said on Tuesday the federation had also filed an official complaint on July 12.
But the prosecutor's office said it had not received it.
Jaminet has apologised on Instagram, saying racism was "unacceptable".
His club Toulon also condemned the remarks and said it was conducting its own investigation.
Several media outlets have reported he was to be questioned at club headquarters on Friday ahead of a possible sanction.
Grill has pledged "zero tolerance" towards anti-social behaviour from players after a series of scandals rocked the team in recent weeks.
Two other players on the France team were arrested and charged with aggravated rape during the same trip to Argentina, where they remain awaiting trial.