Red Bull Motorsport Advisor Helmut Marko has questioned the "manipulative tricks" he feels are being used to peg the team back after a dominant start to the season.
The RB19 has proved largely untouchable in the opening races, with Max Verstappen and Sergio Perez engaged in a private battle for F1's Drivers' Championship.
In Azerbaijan and Miami, the shortening of DRS zones led to widespread criticism from across the grid, with the racing spectacle in Baku particularly diluted by a lack of overtaking manoeuvres.
Red Bull's straight-line efficiency has left the paddock stunned by their pace advantage with DRS activated, and Marko is convinced the shortening of zones in recent races is targeting the championship-leading team.
"Overtaking has always been difficult but especially when the DRS zones are shortened. And we know why that happens..." he told to Motorsport-Magazin. Asked if he believed the changes were aimed at cubing Red Bull's advantage, Marko replied: "Exactly."
"We have to stop intervening with these kinds of manipulative tricks, it is bizarre that Mercedes, of all teams, is moaning.
"For years Mercedes had the superior engine and they were much further ahead of the competition than we are now. And then when you deliver a flop of a car two years in a row, you might be wise to focus on that."