Bernie Ecclestone has admitted that he had been misguided to pay anything to disgraced German banker Gerhard Gribkowsky, but insisted that, in weighing up the alternatives he saw before him, that his actions represented a safer deal.

Gribkowsky, a former chief risk officer at BayernLB, is on trial in Munich for breach of trust and tax evasion over a payment of EUR45m, and admitted on Wednesday that he had accepted bribes during the lender's 2006 off-loading of its stake in the F1 business.

"I allowed myself to be bribed," Gribkowsky conceded, backtracking on denials made eight months ago, before claiming that he had had 'a secret agreement' with Ecclestone to ensure that the 48 per cent holding would go to private equity giant CVC. In exchange, he would be paid a small fortune and be offered a job by the F1 ringmaster. Gribkowsky was arrested in January last year and has been told that he could face up to nine years in prison if found guilty of wrongdoing.

Ecclestone, meanwhile, has admitted to being 'a bit stupid' in getting caught up in the affair, claiming that Gribkowsky had begun to hint at blackmail by releasing details of his tax affairs. As a result, he made a ?10m payment not as an inducement to expedite the deal on CVC's behalf, but to 'keep Gribkowsky quiet'.

"I have always said that we gave him money, but it was not for what he said," Ecclestone told Reuters from Valencia, where he will oversee this weekend's European Grand Prix, "He was shaking me down a bit and saying I had control of a family trust - which was not true. He was doing the best he could. I was a little bit stupid - normally I would have told him to get lost.

"The downside was it could have cost ?2bn, so I paid him. My payment was just over ?10m. As a business guy, I thought that was the better deal."

Ecclestone, who appeared at the trial earlier this year, insists that his tax arrangements have since been cleared by the British authorities.