Red Bull advisor Helmut Marko has defended the timing of the company’s “inappropriate behaviour” investigation into F1 team principal and chief executive Christian Horner.

Horner, the longest-serving team principal on the F1 grid, has been accused of “inappropriate, controlling behaviour” from a female colleague, with the team’s parent company Red Bull GmbH opening an investigation into the 50-year-old’s conduct.

Horner strongly denied the claims when they were first publicised on February 5 and repeated those rebukes at the team’s 2024 F1 car launch last week in Milton Keynes.

With the matter set to drag on into pre-season testing this week - with the first race of the season next Saturday on 2 March - F1 has urged Red Bull to conclude the investigation as soon as possible.

Horner is set to be on the pitwall in Bahrain at testing, which starts on Wednesday, but Marko defended the speed of the team’s probe into the team principal. Speaking to Red Bull’s ServusTV channel about the Horner situation, Marko said: “As you know, this is an internal investigation.

“The sooner a result is available, the better because of course, rumours and other stories are bound to sprout due to the long duration.

“[But] I think Red Bull has reacted very well in this matter. The long duration of this investigation is not their fault. They are endeavouring to [have] a fair investigation and then react accordingly.”

Horner is also due to speak at an F1 press conference alongside four other team principals in Bahrain on Thursday.

While unable to comment on the nature of the investigation at last week’s launch, Horner appeared composed and undeterred by the allegations, continually insisting it was “business as normal” at the world-championship winning team.

“The support from within the business, partners within the industry, has been overwhelming,” Horner told the press at the launch on Thursday.

“Obviously there’s a process that’s ongoing at the moment, some allegations have been made which I fully deny and I’m complying obviously with that process and will continue to do so until its conclusion.”

When asked by The Independent, Horner said he also has the support of drivers Max Verstappen and Sergio Perez.

Red Bull will be the favourites in Formula 1 in 2024 after they stormed to 21 victories in 22 races last year.