The latest witness to testify was Werner Schmidt, the former CEO of BayernLB, for whom Gribkowsky managed the public bank's shares in formula one.
Ecclestone, who argues instead that he was blackmailed, is accused of bribing the already-jailed Gribkowsky to the tune of $44 million to influence the sale of the shares to CVC.
But Kleine Zeitung newspaper reported that, in court on Wednesday, Schmidt told of how Gribkowsky had once asked for a huge multi-million bonus as part of his work on managing the F1 shares sale.
Schmidt said he responded to the request angrily, saying it was "absolutely impossible" to consider giving Gribkowsky a 10 million euro bonus, as others at the bank also "worked day and night at the time".
Kleine Zeitung said Gribkowsky ultimately got nothing extra from Schmidt except his usual half-million euro salary.
Another former BayernLB official also seemed to give the Ecclestone defence another boost when he testified on Wednesday that there were few viable alternatives to selling the F1 shares to CVC.
"It took a long time before we found an interested buyer on the market," said former board member Dieter Burgmer, while ex-CEO Schmidt agreed that the bank was more than pleased with the final price agreed by CVC.