Mercedes have won seven times this season, including in Canada at the weekend, to maintain its 100% record thus far this campaign. Marko's Red Bull haven't been able to really compete with the Silver Arrows - with the team winning six constructors' and drivers' titles in a row.
"Let's put it this way: it's noticeable that the rule changes and decisions lately have always been good for Mercedes," Marko said to Auto Bild. "For example, Pirelli changed the tyre tread for 2019, so they wouldn't overheat, but last year only Mercedes had a problem with them.
"Suddenly in 2019, Mercedes is the only one to get the temperature in the correct working window. Everyone else has not. It's funny. We all had the opportunity to react to it but the cars were designed for less downforce.
"Only Mercedes built a car with a lot of downforce and traction, and in hindsight, that was exactly the way to get the most from these new tyres."
When Marko was quizzed whether Mercedes were receiving some "special treatment" from Formula 1, he wouldn't deny the claim.
"I cannot prove that Mercedes got data earlier than us, but I cannot rule it out," Marko added. "We at Red Bull will look very closely at the future development of Formula 1 and there will also be discussions with Pirelli."