Other than tyres, this is the question on the lips of paddock-dwellers during last weekend's Spanish Grand Prix. As one very well-known name put it to Pitpass' business editor Christian Sylt, "the rumour here is Bernie has got a lot of explaining to do in the next few months because Gribkowsky has dropped his appeal."

In June 2012 a Munich court sentenced Gerhard Gribkowsky to eight-and-a-half years in prison for receiving a £28.6m ($44m) bribe from Bernie Ecclestone - seen here trying out his extradition compound shoes - and his family trust in return for allegedly steering the sale of BayernLB's stake in F1 to current owner CVC in 2006.

German prosecutors believe that Ecclestone wanted CVC to take over F1 because it had agreed to retain him as the boss of the sport. In contrast, Ecclestone says that Gribkowsky threatened to make false allegations about his tax affairs if the £28.6m was not paid.

For the past two years the Munich prosecutor has been investigating Ecclestone and on Monday it confirmed that "the investigation against Mr. Ecclestone has been completed." It follows Gribkowsky dropping his appeal of the judgement against him which was not surprising as he testified in court last year that he was indeed bribed by Ecclestone.

The confession was seen as a move to reduce his sentence because he feared that the court was going to find him guilty anyway. In fact, it led to him being found guilty and German media recently reported that the Ecclestone will be imminently charged with paying the bribe to Gribkowsky. On Sunday Pitpass explained what could be in store if the case comes to trial.

As we pointed out, if the prosecutors bring Ecclestone to court for paying a bribe to Gribkowsky he will give them the biggest battle they have ever seen. He already has one of Germany's top lawyers working for him and he hasn't even been charged with any wrongdoing. If Ecclestone's lawyers prove in court that in fact he is innocent of paying a bribe to Gribkowsky then that raises the serious question of why the banker was found guilty of receiving one. It could cause the prosecutors severe embarrassment, possibly expose them to a damages suit from Gribkowsky and would reduce faith in the German legal system.

This situation could put the prosecutors in somewhat of a Catch 22. The reason for this is that if they don't charge Ecclestone it could equally reduce faith in the German legal system. It could be claimed that Ecclestone needs to be charged with paying the alleged bribe because Gribkowsky was charged with receiving it. So how could the prosecutors escape this Catch 22? One possible answer comes from an article on Monday in weekly news magazine Spiegel one of the most credible publications in Germany.

The author of the Spiegel report was Dinah Deckstein, who has proven herself to be probably the most knowledgeable and reliable reporter on the Gribkowsky case. Spiegel has a circulation of over one million and reportedly employs 80 fact checkers so it is a very credible source.