Niki Lauda has denied rumours that Mercedes might provide engines for Red Bull once their current contract with Renault ends in 2016.
Speculation is rife Red Bull could run with Mercedes engines rebranded as Aston Martin. Mercedes currently hold a 5% stake in the prestigious British car manufacturer.
Lauda, non-executive chairman at Mercedes, told Reuters that the rumours were "a load of rubbish."
"We have not been asked, we never thought about it. That's it," he added.
Motorsport boss at Mercedes, Toto Wolff, would not completely discounting the likelihood of an engine deal with Red Bull happening in the future, however.
Speaking to Autosport, Wolff says that although there were many aspects to take into consideration, an agreement might be reached once Renault had made a final decision about their continued participation in Formula 1.
The French engine supplier is currently undecided as to which route they will follow after 2016. It is believed that they might make a return to Formula 1 by purchasing a current team, or pull out altogether.
"There are many things to be considered," said Wolff.
"What happens if Renault decides to have its own team, to buy another team? Will they continue to supply Toro Rosso and Red Bull?
"If not, what are the solutions? Who is going to supply them to make them stay in the sport?
Although Wolff maintained no talks with Red Bull had yet commenced, he said the door was "open."
"There are no discussions ongoing, nothing has been started, but you need to consider all the options," he said.
"I'm leaving the door open."
Speculation rose over the past weekend's British Grand Prix when Andy Palmer, the boss of Aston Martin, was spotted in the paddock.
Red Bull team principal Chirstian Horner, told Autosport that he had not been invited by the Milton Keynes based team.
"Andy Palmer was here this weekend on a Force India pass," he said.
Horner would not be drawn into a discussion about any future engine contracts. Red Bull have also been linked with Ferrari in the past few weeks.
"Last week it was Ferrari, this week it's Aston Martin, next week it will probably be Honda or Lamborghini," he said.
Although he pointed out that Red Bull were committed to their current deal with Renault.
"The fact is, we have a contract with Infiniti and Renault until the end of 2016. Anything beyond that is pure speculation."