Red Bull owner Dietrich Mateschitz has expressed concern over the implications of Formula 1's planned budget cap.
The revived cost cap plan was announced as part of a package of imminent changes at the end of 2013, with the intention being to introduce it next season.
Discussions about the exact format of the budget restrictions are still taking place, but Mateschitz has misgivings about the potential format and how it would be enforced.
"To enforce a budget cap you have to clearly state what is included and what not - what about marketing, drivers' salaries etc?" he said.
"And what if you are a manufacturer and can hide several expenses in other budgets?"
Mateschitz also questioned the expense involved in implementing the 2014 regulations.
"Given all the costs the manufacturers and teams had to take by the new engine formula, we spent close to a billion euros all together," he said.
"Is there any questioning on this?
"And the windtunnel hours: we use an existing work tool that is already there, so what?
"These expenses are clearly less than those for new rules and engines."
Red Bull has won the past four F1 drivers' and constructors' titles, but had a difficult start to its 2014 programme in testing at Jerez this week.