Riner, a multiple Olympic and world champion judoka, is one of French sport's most popular figures.
During an interview with sports television show Stade 2 last week, he said he was “freaked out” by the rise of extremism.
Asked if he meant “on both sides” – meaning the far left and the far right – Riner replied: “The far right."
France's presidential election is being held next April and Marine Le Pen's far-right, anti-immigration National Rally party is polling ahead.
Following the interview, Riner received numerous racist insuts and hate messages online, the Public Prosecutor's Office said.
In a brief statement posted on Instagram on Wednesday, the office said it had opened an investigation into "racist insults and cyber harassment targeting a French athlete," alongside a picture of Riner competing.
The Central Office for the Fight Against Crimes against Humanity and Hate Crimes (OCLCH) will lead the investigation. Teddy Riner receives Legion d'Honneur medal from President Macron on 14 September, 2024 following the judoka's performance at the Paris Olympics.
Tens of thousands in France protest against racism and far right
PSG support
Riner, 37, was born on the French Caribbean island of Guadeloupe and grew up in Paris.
He was the most decorated judoka at the Paris Olympics, and has been named France's favourite sportsperson at least five times – most recently in 2023.
“Following my remarks on 16 September, numerous tweets, posts, comments and messages of a hateful or racist nature directed at me have circulated on social media”, he posted on Instagram on Thursday. "Debate and contradiction are legitimate. Hatred and racism are not."
“I love France deeply – I'm defending its history, its talent, its heritage, its republican values and its diversity," he added.
On 16 September, Riner re-joined Paris Saint-Germain's judo club on a contract lasting until 2028. PSG expressed its full support for Riner.
“Racist insults and hateful messages targeting Teddy Riner are unacceptable,” the club posted on X. “They have no place on social media, in sport or in our society.”
Mbappe condemns racist abuse by Paraguayan senator after World Cup clash
Kylian Mbappé, the French national football team's captain, was similarly targeted in May when he expressed concerns that the National Rally party could win the 2027 presidential election.
In an interview with Vanity Fair magazine he said: “I know what it means and what consequences it can have for my country when people like them come to power.”
(with newswires)



Bolgatanga: Man found dead by roadside in Sumbrungu as police investigate
Ghana concludes cocoa freight negotiations for 2026/27 season
Blakk Rasta accuses Gushegu NPP MP Alhassan Tampuli of funding Ghana Jollof atta...
€225m Cocaine Shipment: Court to rule on bail application of six accused in 3.9-...
BoG pilots cedi-based payment system for Ghana-China trade
2026 BECE: Ten schools score zero percent in Adaklu as girls outperformed boys
Gold shipments resume as Ghana rebuilds foreign exchange reserves — BoG governor
ECG unions to stage nationwide protest over proposed private sector participatio...
‘That penalty is a joke’ — Queiroz rejects referee decision in Ghana’s loss to C...
'Sceptics, naysayers, alarmists should be aware US ready to work with Ghana on r...
