His recent designs have absolutely dominated the sport since the current ground-effect regulations were introduced in 2022, with Red Bull winning 25 of the last 27 races.

Newey is one of the most revered and successful figures in Formula 1's history and had previously designed multiple title-winning cars for McLaren and Williams before being convinced by Horner to join a then-fledgling Red Bull team in 2006.

Red Bull confirmed in May 2023 that Newey had signed a contract extension, which it has now emerged runs until at least the end of the 2025 season.

Is Verstappen's future in doubt once more?

Since the allegations against Horner became public, the majority of the media's focus has been on whether uncertainty at the top of the team could result in Verstappen making a shock departure from a car that has brought him a historical level of dominance.

The saga reached its most heightened point during March's Saudi Arabian Grand Prix when, amid reports Marko was on the verge of leaving, Verstappen suggested he could follow the Austrian out of the team.

The situation appeared to have calmed during the three races that followed, but Mercedes boss Toto Wolff notably said in China last weekend that he - and the rest of F1 - were still "waiting" on Verstappen to make a decision over his future as the 2025 grid takes shape.

The comment from Wolff, who has admitted he would "love" for Verstappen to fill the vacancy left at Mercedes by Lewis Hamilton's move to Ferrari, appeared odd given the apparent easing of tension at Red Bull, along with Mercedes' struggles on track, but now suddenly make a lot more sense.

Whether or not Wolff knew the Newey bombshell was coming, there is no doubt that his departure from Red Bull would dent the team's chances of maintaining their position at the front of the grid when radical new regulations are introduced for the 2026 season.

With Red Bull manufacturing their own engine for the first time for the 2026 season, the absence of Newey would add another huge question mark as to whether they can create a title-challenging car.

Verstappen is contracted until 2028 but has previously admitted that whether Red Bull are able to keep delivering him a winning car will play a role in whether he sees out the deal, which is understood to contain exit clauses.

It will be fascinating to see what the straight-talking Dutchman has to say about Newey's decision when he faces the media ahead of next weekend's Miami Grand Prix.

A huge blow for Horner

Losing Verstappen as well as Newey would be a total disaster for Horner, but the latter alone is a seismic blow.

BBC Sport is among the outlets reporting that Newey's exit is directly related to how he feels about Horner.

Newey has yet to comment since reports of his desire to leave emerged, but the suggestion that the sport's undisputed best car designer is departing the team because of Horner, creates terrible optics for the team principal.