Sports director Patrick Moster was caught on camera using derogatory language when urging Nikias Arndt to try to catch Eritrean rider Amanuel Ghebreigzabhier and Algeria's Azzedine Lagab on the road, with the comments clearly audible on German station ARD's broadcast of the race.

ARD commentator Florian Nass was left stunned, describing the comments as "totally wrong".

"Words fail me," he added. "Something like that has no place in sport."

Former rider Moster, who is 54 and has been in his current role since 2012, appeared in the mixed zone at the Fuji Speedway to apologise for his actions.

"I was in the feed zone and cheered on Nikias Arndt," Moster told reporters.

"In the heat of the moment and with the overall burden that we have here at the moment, my choice of words was wrong. I am sorry, I'm so sorry, I can only sincerely apologise. I didn't mean to discredit anyone."

It is understood Moster attempted to visit the Algerian team in the paddock to apologise directly, but the team had already left.

Arndt said Moster's comments were unacceptable.

"I am appalled by what happened in today's Olympic road time trial," Arndt said on social media. "I would like hereby to clearly distance myself from the comments of the sports director. Such words are not acceptable."

A statement from the German Olympic Federation said: "Team Germany represents Olympic values like respect, fair play and tolerance throughout the competitions and beyond.

"It is important that Moster apologised while the race was still on. Nonetheless we will discuss the matter with him directly."

- with Reuters

Australian Associated Press