Indignant: Miller says he is also in the dark

The case centres on allegations that a film producer tried to get money from a newspaper editor, saying he could influence forthcoming government legislation on media ownership in the newspaper's favour.

In his testimony, shown live on Polish television, Mr Miller dismissed any suggestion that the media law might have been changed.

He said a bribe would have made no sense, at a time when the government and media had already agreed on the shape of the new law.

'Rywingate'

Mr Miller's appearance had been keenly awaited in the case, known in Poland as "Rywingate".

The scandal has dominated the headlines of Polish papers for months, the BBC's Nicholas Walton in Warsaw says.

At its heart is the allegation that a film producer, Lew Rywin, tried to obtain a bribe of $17.5m from a newspaper editor, in return saying he could arrange for government legislation to be altered in the owner's favour.

Yes camp: Poland will vote on EU membership in June

Adam Michnik, the editor in chief of Gazeta Wyborcza, refused, but waited almost six months to publish the story, saying this was to protect Poland's negotiations to join the European Union.

Mr Miller told the commission he was not capable of explaining what happened. But he said that, as somebody who had been defamed and wronged by allegations, he was himself deeply interested in an explanation.

Mr Miller said a false image of Poland was being created, with corruption allegations reaching the highest bodies of power.

Many Poles, already very unhappy with their government, have been disillusioned by the scandal, which has confirmed in many minds the levels of corruption in their country, our correspondent says.

He says the case is bad news for those worried about low voter turnout in June's EU referendum.