It is possible that we are on the verge of one the the biggest scandals to have ever hit Formula One, or one of the greatest farces.

The FIA has overruled the clean bill of health its own Stewards gave to BAR following a six hour inspection after the San Marino GP and an appeal is set for Wednesday, 4th May, immediately before the Spanish GP.

The fact that the FIA has overruled its own Stewards suggests that it believes it has evidence which overrides the best information that the Steward's had to hand. That can only mean that it has documentation which is independent of the car which was examined at Imola.

Pending the hearing, Jenson Button's BAR Honda has been dropped from the results of the race at Imola for being underweight. During post race scrutineering, BAR was able to produce data which convinced the Stewards that the car ran legally during the race.

It is alleged that the BAR had a secret fuel tank and, a theory goes, it ran underweight during the race. During its final stop, so goes this theory, the car took on enough fuel to complete the race plus extra litres which became ballast to bring the car up to the minimum legal limit.

This does not make sense to me. If there was a secret ballast tank, the car would not be underweight. Cars can be weighed at any time during a Grand Prix weekend and in Charlie Whiting, the Technical Delegate, we have a poacher turned gamekeeper. Charlie knows about scams, he spent ten years at Brabham when Bernie ran the team. Brabhams sometimes ran underweight during qualifying and then the heavyweight body panels would be substituted for the trip to the scales.

Every car on the grid at a modern GP is weighed after qualifying so we know they start a race in legal trim.

Where on earth do you put a rogue tank on a Formula One car? The pipes would give it away. Three very experienced Stewards went over the car for six hours and they found nothing wrong.

Here is a question: is it usual for stewards to spend six hours examining a car which was weighed after the race and found to be legal? To the outsider it might appear that they were told to find something and, when they found nothing, the FIA overruled them.

The obvious place to put a secondary fuel tank is inside the main bag tank and the rules say there can only be a single bag. Why would one wish to add a secondary tank? One reason might be ensure that the fuel that goes to the engine has no contact with air. I do not believe that there is any rule which forbids a designer from ensuring that only pure fuel, without the possibility of air bubbles, reaches the engine. When you have ten cylinders, each going bang 160 times a second, such details can be critical.

We have heard that some engineers suspect that BAR ran underweight last season. We know of one who believed the car was underweight at Imola, and he expressed that opinion before the scrutineering was over but the scrutineers pass the car.

It is possible there has long been suspicions about the BAR and the matter only came up at Imola because it was the first time in 2005 that one has finished. The classic scam used to be to run well in a race to impress potential sponsors and then fail to finish so the car escaped scrutineering.

Why would the matter arise in 2005 when some engineers allege that the team had cheated in 2004? One purely pragmatic reason is that when an engineer moves from team A to team B, he takes some of A's information to B. This happens all the time which is why senior engineers are put on gardening leave towards the end of their contracts so they cannot take the very latest information to another team.