LONDON  - Formula One chief Bernie Ecclestone was accused of striking a "corrupt bargain" in a bid to maintain his grip on the sport, at the start of a hearing in London's High Court on Tuesday. A German media group, Constantin Medien, which claims it lost out in a deal to sell the Formula One group, has launched legal action against the 83-year-old British tycoon and three other defendants.

Swiss prosecutors announced Tuesday they were opening their own probe into the issue, in the latest challenge to Ecclestone's authority in a sport he had helped turn into a billion-dollar business. Ecclestone was not in court on Tuesday but is expected to give evidence next week.

The key charge levelled against him is that in 2005 he paid $44 million (32 million euros) in bribes to a German banker to engineer the sale of Formula One to current owners CVC Capital Partners. A lawyer representing the German media group told the High Court that Ecclestone entered into the "corrupt agreement" with a banker to facilitate the sale of the Formula One group to a buyer "chosen" by him.

Constantin is seeking more than $100 million in damages. Robert Miles, representing Ecclestone, said the claim "lacks any merit". "In short, this is an artificial, manufactured, complaint," Miles told the court. "The claim fails on each of its elements. There was no conspiracy, there was no intent to injure Constantin ... Constantin has suffered no loss."

Gerhard Gribkowsky, formerly the chief risk officer of German bank BayernLB, has been jailed for eight-and-a-half years by a Munich court for receiving corrupt payments. Ecclestone does not deny paying Gribkowsky but insists he was the victim of a blackmail plot by the German.

Constantin Medien, which owned an interest in Formula One via BayernLB, which held 47 percent of the stock, alleges that the $820 million price paid by CVC was intentionally undervalued.

Within months of the deal, the value of CVC's stake had reportedly jumped to $2.8 billion, making it one of the most profitable deals in the private equity group's history. Prosecutors in Germany have also probed the affair. Last month, prosecutors in Munich delayed setting a date for Ecclestone to stand trial on bribery charges until next year. Swiss prosecutors said Tuesday they had also opened an investigation.

"The Geneva prosecutor's office has opened an investigation following a complaint by the company Constantin Medien," spokesman Henri Della Casa told AFP. The spokesman declined to name Ecclestone directly, but confirmed the accuracy of media reports that said he was the target of the investigation. The decision to open a probe in no way implies any wrongdoing on Swiss soil, Della Casa said.

"The goal is to establish whether the facts constitute an offence under Swiss criminal law," he said. The legal wrangling has cast a shadow over renewed plans to float Formula One which were put on hold last year due to rocky markets. CVC is reportedly seeking a valuation of more than $10 billion if the flotation goes ahead.