The French Rugby Federation (FFR) and the French league (LNR) said on Monday they will launch a joint disciplinary investigation after a Cameroonian player was racially abused playing in the second-tier ProD2 at the weekend.
Nevers' Cameroonian winger Christian Ambadiang said he had been called a "banana eater" by an opposition player during Friday's loss at Aix-en-Provence.
Earlier on Monday, the hosts' scrum-half Ludovic Radosavljevic, who spent 12 years in the Top 14 with Clermont and Castres, apologised for using the terminology.
"This joint investigation, on the part of two bodies committed to the promotion of diversity, is focusing on the unacceptable remarks by the Aix-en-Provence player Ludovic Radosavljevic towards the Nevers player Christian Ambadiang," they said.
"The FFR and the LNR also want to underline the exemplary attitude of the two clubs who have engaged in quick and responsible dialogue with the different parties," they added.
Ambadiang, 22, who is in his second season in ProD2, France's tier below the Top 14, after joining from Western Province's academy in South Africa, received support from across the rugby world.
"Speak your truth bro," former New Zealand hooker Hika Elliot said on Instagram.
Former Clermont half-back Radosavljevic, 32, was criticised by France back-rower Sekou Macalou.
"Too easy to apologise afterwards. Here's to hoping the club and the league punish heavily this type of... #NoRacism," Macalou said on Instagram.
The results of the investigation are likely to be published over the coming days.