Mercedes F1 boss Toto Wolff has strongly denied cheating after rival team Red Bull Racing asked for clarification over a possible breach of regulations.
Red Bull's team principal, Christian Horner, wrote to the sport's governing body, the FIA, earlier this month, seeking clarity about rules on burning oil as a fuel to gain extra power during qualifying.
It seems that Red Bull believes Mercedes has been using the ploy, which would break the rules as only certain chemicals are allowed to be used to power the V6 engine.
Wolff, however, was adamant that though the team does have an engine mode (known as a map) that allows the car to use more power for qualifying runs, the team had not broken the rules.
The Austrian told the Daily Mail: "They must be seeing ghosts. For years we've had a map that allows us to use more horsepower in qualifying. This is nothing new. Maybe there will be protests, but Mercedes feel safe."
According to Autosport, the FIA has confirmed that burning oil as fuel would be a breach of the regulations, but the body accepts that oil "consumption" was an inevitable side effect of running an internal combustion engine.
The 2017 Formula 1 season starts this weekend, with the first round taking place at Albert Park in Melbourne, Australia.