Dr Helmut Marko has admitted to being in talks with Porsche.
Reports emerged last week that the Volkswagen brand is eyeing Formula 1's new engine regulations for 2025.
Marko then told Servus TV that Red Bull is "speaking to companies about possible partnerships" now that the team will run its own engine program from 2022.
When asked specifically about Porsche, the Red Bull official said: "We are talking. But nothing is fixed."
A Porsche spokesman, however, would not comment on the story when contacted by Sport1.
But the German news source said Marko is already close to several VW and Porsche figures, including Fritz Enzinger, Herbert Diess and even Wolfgang Porsche.
Marko said: "It's too early to talk about specifics, but it is no secret that we have had discussions with manufacturers in the past. We are open to partners.
"We can even imagine building a new engine for the new regulations without a partner from the industry," he added. "But a partnership with a big manufacturer would of course be the ideal scenario."
Meanwhile, Marko said the clear goal for 2021 is to win the world championship. But he also admitted that Red Bull will need to work hard to keep Max Verstappen on board for 2022.
"We just have to provide Max with a car that is capable of winning, and then nothing will stand in the way of a further cooperation," said the Austrian.
