The Formula 1 paddock was set alight with controversy ahead of the Monaco Grand Prix as McLaren CEO Zak Brown accused Red Bull of stealing their innovative rear tire temperature control system, a technology he claims gave Max Verstappen a critical edge in recent races. The allegations, made public in a fiery interview with Sky Sports on the eve of FP1 in Monte Carlo, have reignited tensions between the two teams, who are locked in a fierce battle for the 2025 championship. Brown’s comments come after Red Bull’s surprising resurgence at Imola, where Verstappen snapped McLaren’s dominant run with a commanding victory, raising suspicions about the source of Red Bull’s improved tire management.

McLaren has been the pacesetter for much of the 2025 season, with Oscar Piastri and Lando Norris winning five of the first six races, thanks largely to the MCL39’s superior tire preservation, as noted by team principal Andrea Stella in an Autogear.pt interview. The team’s innovative brake cooling system, designed to minimize heat transfer to the tires, has been a key factor in their long-run pace, particularly in hot conditions like Bahrain and Miami. However, Red Bull’s upgrades at Imola—including a revised rear suspension and engine cover resembling McLaren’s design—allowed Verstappen to outpace both McLaren drivers, prompting Brown to question the legitimacy of Red Bull’s sudden improvement. “It’s curious how their tire wear suddenly matched ours after months of struggling,” Brown remarked, hinting that Red Bull may have replicated McLaren’s proprietary fluid-based tire temperature control system.

The controversy echoes earlier tensions in Miami, where Red Bull speculated that McLaren was injecting water into their tires to cool them, a claim Brown dismissed with a cheeky “tire water” stunt, as reported by PlanetF1.com. The FIA investigated McLaren’s brake design and found no breaches, clearing them of wrongdoing. Now, Brown has turned the tables, suggesting Red Bull’s Imola upgrades suspiciously mirror McLaren’s technology. “We’ve spent years developing our system,” Brown told Sky Sports. “To see a near-identical solution appear on a rival car after they’ve been poking around our garage raises questions.” While Brown stopped short of demanding an FIA investigation, he called for transparency, urging teams to “play fair” in the spirit of the sport.

Red Bull team principal Christian Horner dismissed the accusations as “baseless,” crediting their Imola success to legitimate upgrades and Verstappen’s brilliance, particularly his audacious first-lap overtake on Piastri, as highlighted by Formula1.com. “Max drove a flawless race, and our upgrades worked as planned,” Horner said, per The Guardian. He suggested McLaren’s complaints stem from frustration at losing their edge, noting that Red Bull’s revised suspension and geometry tweaks improved tire degradation, a critical factor in high-temperature races. However, Brown countered that Red Bull’s access to McLaren’s garage during fan zone events could have facilitated espionage, a claim Horner called “paranoid.”

The Monaco Grand Prix, with its tight, low-speed layout, is expected to favor McLaren’s MCL39, which excels in tire management on slower circuits, according to BBC Sport. Verstappen, however, expressed concerns about the RB21’s handling on street tracks, telling PlanetF1.com that current F1 cars feel “clumsy” in Monaco’s tight corners. Despite this, Red Bull’s recent upgrades have narrowed the gap, with Verstappen now just 22 points behind championship leader Piastri and nine behind Norris, per Motorsport.com. McLaren’s refusal to impose team orders, as seen in Imola when Norris overtook Piastri late, underscores their confidence in their car’s pace, but it also highlights the pressure to maintain their lead against a resurgent Red Bull.

The FIA has yet to respond formally to Brown’s accusations, but new technical directives issued before Imola, as reported by RacingNews365.com, emphasize stricter oversight of tire and brake systems. McLaren’s dominance—132 points ahead of Mercedes in the constructors’ standings—remains intact, but Verstappen’s Imola win, Red Bull’s 400th race, has shifted momentum. As Monaco’s FP1 looms, all eyes are on whether McLaren can reclaim their edge or if Red Bull’s alleged “stolen” technology will keep Verstappen ahead. The controversy adds fuel to an already intense rivalry, with Brown’s accusations raising the stakes for a weekend where qualifying pace and tire strategy will be paramount on the unforgiving streets of Monte Carlo.