Red Bull has fended off the latest round of speculation, as tales of cheating and overspending refuse to go away.
Germany's Bild newspaper said the culprits of the renewed allegations about the back to back world champions are McLaren and Ferrari, reportedly concerned that the FOTA cost-limiting agreement has not been honoured.
"Ludicrous," Dr Helmut Marko, Red Bull's motor racing consultant, hit back.
"It is the jealously of poor losers, throwing mud and hoping something sticks."
The major German daily on Saturday published some previously unknown details of the accusations.
The first is that Red Bull has engaged more than the allowed 350 staff for the direct design, construction and development of the car.
"That's not true," said Marko. "The other top teams simply need to realise that we work more efficiently than they do."
The second accusation is that Red Bull has operated its wind tunnel longer than the allowable hours according to the resource restriction agreement (RRA).
Our wind tunnel is an antique, 80 years old and three times bigger
"Our wind tunnel is an antique, 80 years old and three times bigger than a modern one. It just takes longer to get going, and so only when it is (running) do we begin to measure (the time)," explained Marko.
Another charge is that Red Bull has refused to let inspectors check the team's adherence to the RRA during inspections.
Marko insisted: "We have provided the information that we had to and nothing more."