World champion Peter Sagan has fended off a question about the controversy involving fellow cycling star Chris Froome, saying he cannot comment.
A media officer for Sagan's team Bora-Hansgrohe then shut down any further questions about the issue.
It highlights the sensitivity around the ongoing investigation into Froome, the four-time Tour de France champion.
A urine test that Froome gave at last year's Tour of Spain allegedly showed twice the legal limit for the anti-asthma drug salbutamol.
Froome is preparing a defence for authorities.
It is a massive issue for the sport and new world cycling boss David Lappartient, visiting Adelaide for the Tour Down Under, was quoted as saying he hopes the issue will be resolved before Froome is scheduled to start in the May Giro d'Italia.
Sagan was asked about Froome in a media conference on Friday evening at the Adelaide Tour.
"Well, I can't respond - (we are) thoroughly different riders," Sagan said.
"I've never ridden with him in the same team and then we will see what they (the authorities) are going to decide."
A media officer for Sagan's Bora-Hansgrohe team then told Sagan not to answer a follow-up question about Froome.
This week, French star Romain Bardet questioned whether Froome should not compete until the matter is resolved.
Sagan held the media conference hours after he rode superbly to win stage four at the Tour Down Under and take the race lead.
It is the first time in the Tour's 20-year history that the reigning world champion has won a stage, or been in the overall lead.
