Helmut Marko has accused Christian Horner of 'lying about everything and anything' towards the end of his time as Red Bull team principal - claiming that it led to his eventual sacking.
Marko's own departure from Red Bull was confirmed on Tuesday following the season-ending Abu Dhabi Grand Prix.
The 82-year-old has been a part of Red Bull Racing since the team was founded in 2004, and was serving as a director to Red Bull Racing through the energy drinks giant's parent company, Red Bull GmbH, at the time of his departure.
Autosport's Ronald Vording reported that there had been growing tensions between Marko and the F1 team's management in the build-up to his exit.
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It is reported that he signed off on a contract to bring former McLaren junior Alex Dunne to the Red Bull driver development programme, but that it was against the wishes of management, who paid compensation to terminate the deal.
Red Bull also issued an official apology after the Austrian claimed Kimi Antonelli had 'waved past' Lando Norris in the closing stages of the Qatar Grand Prix.
Marko is the latest in a series of notable departures at Red Bull Racing since the death of co-founder Dietrich Mateschitz in 2022.
Technical chief Adrian Newey and sporting director Jonathan Wheatley, who had both been with the team since 2006, left last year and are now the team principals of Aston Martin and Sauber - to be rebranded as Audi from 2026 - respectively.
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Head of race strategy Will Courteney also departed in 2024 to join McLaren.
And this season, team principal Horner - who had overseen all of Red Bull's F1 races - was sacked by the team before the Belgian Grand Prix.
He was initially placed on gardening leave, but subsequently negotiated an eight-figure pay-off which differing reports have claimed is between £52 and £75 million.
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Horner can officially return to Formula 1 in 2026, though has yet to find work and was recently overlooked for the Aston Martin role in favour of Newey, who was already serving as technical director.
There have been various reports of a power struggle at Red Bull following the death of Mateschitz, who passed away at the age of 78 in October 2022.
The Yoovidhya family, from Thailand, held until recently a 51 per cent stake in Red Bull, with F1-Insider claiming that Mateschitz had a 'managing director agreement' that would give him 'free rein to make various operational decisions' independently.
It was also claimed that following his death, the agreement was not transferred.
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A 49 per cent share is held by the family of Thai businessman Chaleo Yoovidhya, who passed away at the age of 88 in 2012.
With Mateschitz holding an equal 49 per cent, the other two per cent stake was held by Yoovidhya's son, Chalerm, making him the majority shareholder when combined with his family's holdings.
A document from Austria's Companies House showed that the 75-year-old had transferred his two per cent share to a Geneva-based trust company in May. Horner was sacked in July, though there is no indication that the transfer meant Yoovidhya relinquished any power at Red Bull.
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Now, Marko has made a series of sensational claims about the end of Horner's time at Red Bull - including alleged private conversations with Yoovidhya.
"When Didi died, Horner did everything he could to take over with the support of Chalerm Yoovidhya," Marko told Dutch publication De Limburger.
"On behalf of Austria [where Red Bull's HQ and base is situated], I did everything I could to prevent that.
"We had to do something, because our on-track performance was lagging.
"If we had done that sooner [removing Horner], we would have gotten back on track faster this year, and Max would have become world champion. I'm absolutely convinced of that.
"We were increasingly able to demonstrate that Horner was lying about everything and anything. Once Chalerm realized this, he came to his senses."
SPORTbible have contacted Christian Horner's representatives for comment.
Topics: Red Bull Racing, Formula 1, Christian Horner, Helmut Marko
Ryan Smart