After an internal investigation, Red Bull have dismissed the allegations against Horner and the colleague has been suspended.
Vettel discusses Horner allegations
Sebastian Vettel, usually outspoken on social issues within the paddock from the environment to women’s rights, has re-entered the public sphere of motorsport.
In a recent interview with Sky Germany, the German driver discussed his return to the track with a hypercar test for Porsche Penske.
Vettel was also asked about the allegations surrounding Christian Horner, to which he called for greater transparency.
He said: "Of course, I still know the team, Christian [Horner] and Dr. Marko very well, also from my time there. But it is very difficult for me to have an opinion because you don't know what happened and what didn't happen. I think people would like a bit more transparency in this respect, but I hope with time this will all be clarified."
"I believe that processes can become visible, provided people dare to take certain steps. I think from the principle that you have nothing to hide, you should not shy away from transparency.
"This applies to sport in general. I think many viewers would be interested in this. But if the information were accessible, many questions could be answered on their own."