by Our Foreign Desk

Brazilian state-owned oil company Petrobras revealed on Wednesday that it had lost 6.2 billion reais (£1.4bn) because of endemic corruption over a period of eight years.

The company released its long-delayed fourth-quarter financial results which included a write-down of that sum based on losses linked to inflated contracts and other stratagems during a scheme that ran from 2004 to 2012.

The scheme involved executives taking bribes for awarding inflated contracts to suppliers.

Releasing the audited results was the first step for Petrobras to try to regain investor confidence and access to international credit markets, which the debt-plagued company desperately needs to develop huge offshore oil fields discovered in recent years.

The company was cut to junk status by one international rating agency in late February, largely because of the scandal.

Federal prosecutors say that their probe has revealed the largest corruption scheme ever uncovered in Brazil.

They stress that they are still investigating and the case is widening, with dozens of top business executives, federal legislators and other political figures facing charges, under investigation or already in jail.

Investigators say that the scheme involved Brazil’s top construction and engineering companies paying bribes to a handful of politically appointed Petrobras executives in return for winning inflated contracts.

Prosecutors allege that some of the money then flowed into the campaign coffers of the ruling Workers’ Party and its allies, which they deny.

In addition to the dozens of executives who have been charged in the case, the Attorney General’s office said last month that it was investigating more than 50 political figures, including 21 federal deputies and 12 senators, for alleged participation in the fiddling.

Among those under investigation are the leaders of both houses of congress.

President Dilma Rousseff, who chaired the Petrobras board during most of the years the scheme played out, has not been implicated in the case.

She has expressed strong support for the investigation and for holding the guilty accountable.

But the investigation crept closer to her this month when Workers’ Party treasurer Joao Vaccari was arrested and charged with money-laundering for handling funds connected to the Petrobras kickback scheme.