Former Brazil Workers' Party treasurer sentenced for corruption

Vaccari, who denies the charges, remained in silence during the trial

The former treasurer of Brazil's governing Workers' Party, Joao Vaccari Neto, has been sentenced to 15 years and four months in jail for corruption and money laundering.

He is the closest person yet to President Dilma Rousseff to be sentenced over the case, which has led to calls for her impeachment.

But prosecutors say there is nothing to implicate her directly.

A former director of the state oil giant Petrobras was also sentenced.

Renato Duque, the former director of services at Petrobras, got 20 years and eight months.

Vaccari and Duque deny the charges. They are expected to appeal.

These are the longest and the most significant sentences yet in a corruption scandal that is undermining the stability and authority of President Rousseff's government, says the BBC's Wyre Davies in Rio de Janeiro.

Government supporters accuse conservative politicians and businessmen of attempting to associate the corruption at Petrobras with the Workers Party in order to topple her left-wing government.

'Damage to democracy'

Federal Judge Sergio Moro said that at the request of Vaccari, Duque made 24 payments to the Workers' Party between 2008 and 2010.

"Enough," says the banner on a President Rousseff doll at a recent protest

The "donations" totalled 4.2m reais (£700m;$1m).

"It looked like an old debt was being paid by instalments," said Judge Moro.

"The money laundering has had an impact on the democratic process, contaminating it with criminal resources," he added.

Investigators say that for many years Brazil's biggest construction companies paid multi-million dollar bribes to politicians, and senior officials at Petrobras, to secure lucrative contracts.

Dozens of politicians, civil servants and businessmen have been detained or charged over the past year.

The investigation has been dubbed Operation Car Wash, after a petrol station in Brasilia where illegal dollar transactions were alleged to have taken place.

Data retrieved from the Petrobras case has led to evidence of corruption in other areas.

Last month, Brazilian prosecutors launched a probe on allegations corruption and overpricing in the construction of a stadium used during last year's football World Cup.

They believe building construction giant Odebrecht inflated the price of the Arena Pernambuco by $12m (£7.8m).

The company's president, Marcelo Odebrecht, has been charged with corruption in the Petrobras case. He denies any wrongdoing.