Ousted Tunisian president Zine el Abidine Ben Ali denounced his "legally insane" 35-year jail sentence for embezzling public funds, his Paris-based lawyer said overnight.

Ben Ali said that "after less than two hours of hearings ... the court [in Tunis] delivered a sentence that is judicially insane but politically opportune", lawyer Jean-Yves Le Borgne said in a statement.

The ousted strongman viewed the court's speedy verdict on Monday, reached after just six hours of deliberations on the first day of the landmark trial, as a "parody of justice", the statement added.

The "political liquidation ... expresses the blind hatred of the past that fails to hide the lack of any vision of the future", it said.

Ben Ali and his wife, Leila Trabelsi were charged with embezzlement after the discovery of money and jewellery at their palace on the outskirts of Tunis.

The ex-president was also fined $34.4 million, while his wife was fined $28.2 million.

Judge Touhami Hafi said the sentences, which exceeded the 20 years that had been widely predicted, would take immediate effect despite the couple living in exile in Saudi Arabia, which has so far ignored Tunisia's demands to extradite them.

Some Tunisians have criticised the trial.

"It is a big disappointment, the kind of charade of summary justice that the dictatorship had accustomed us to," said Mouhieddine Cherbib of a France-based Tunisian rights group.

"We wanted a real trial, a fair one ... a trial of the dictatorship with people who were tortured appearing as witnesses - a justice system from which you learn something," Mr Cherbib said, adding that high treason would have been a more appropriate charge.

The United States, however, hailed the ruling as "a big step forward".

"Just the fact that there was a legal process is already progress," State Department spokeswoman Victoria Nuland told reporters.

"If you look at where we were with justice and accountability issues with Tunisia as recently as six months ago, the fact that there was a trial, the fact that... it was an accountable legal process is a big step forward," she said.

"The fact that the Tunisians are making progress from where they were just six months ago in terms of rule of law, is something that we are gratified to see."

- AFP