Intrigue has threatened to derail the Monaco Grand Prix in the build-up to the race as rumours of a post-race protest took hold.

It's claimed the Red Bull car contains a hole in the floor just ahead of the front wing in what many believe to be an exclusion zone. The FIA deemed it a clever interpretation of the regulations when they declared it legal, though that conclusion isn't shared by a number of rival teams.

The solution is believed to have been on the car since as early as the Malaysian Grand Prix, though the simple fact that it's been there for a number of races does not mean it is legal or that it won't be protested.

Teams have two hours after the release of the official results in which to lodge a protest, which if upheld could see both Mark Webber and Sebastian Vettel excluded from the race.

It's the second time this season that technical developments have created waves after Mercedes was forced to defend it's 'double DRS' system. Protests lodged by Lotus were dismissed at the time, though Ross Brawn was unimpressed that the situation had reached that point.

"To protest someone after they've been through qualifying is a bit unpleasant and certainly not something we would intentionally do," said Brawn ahead of the season opening Australian Grand Prix. "We've never done that and a protest after qualifying or after a race is not very pleasant because it can be done on a Thursday or it can be done on a Friday when it's less critical."

Ironically it's believed Mercedes, along with McLaren and Ferrari, are believed to be considering a post-race protest. For his part Christian Horner is defiant, satisfied that the system is legal. Speaking with Sky ahead of the race he confirmed the team has no intention of removing it ahead of today's Monaco Grand Prix.