SAO PAULO, Dec 12 (Reuters) - The chief executive of Brazil's state-run oil company Petroleo Brasileiro SA was warned about inflated costs at refinery projects years before prosecutors started investigating an alleged kickback scheme, newspaper Valor Economico reported on Friday.
The paper cited documents provided by former Petrobras executive Venina Velosa da Fonseca. She first notified employees, including the company's then-director of gas and energy Maria das Graças Foster, about inflated contracts on April 3, 2009, Valor reported, citing her allegations.
Foster was also warned of irregularities after she became chief executive of Petrobras, as the company is commonly known, in 2012, the paper said.
Brazilian prosecutors on Thursday indicted 36 people, including executives from some of the country's largest construction and engineering firms, for allegedly skimming billions of dollars off contracts with Petrobras in recent years.
Only one former Petrobras executive, Paulo Roberto Costa, was among the accused. He has admitted involvement in many of the alleged crimes and has been aiding prosecutors.
Da Fonseca was transferred to Singapore in 2010 and fired from the company last month. She has not been cited by prosecutors in the investigation, Valor reported.
The investigation, known as Operation Car Wash, started in March, and prosecutors intend to present more charges in coming months. They will also present names of politicians allegedly involved in the scheme to the Supreme Court, which has sole jurisdiction over sitting legislators and top government officials in Brazil.
Petrobras said in an emailed statement that Da Fonseca had been fired in 2009 for breach of procurement procedures but that her official departure had been delayed due to medical leave.
Brazilian President Dilma Rousseff, who chaired the Petrobras board from 2003 to 2010, has denied knowledge or involvement of the scheme.
Valor said the hundreds of documents it had reviewed showed Petrobras paid millions for services that were never completed.
Petrobras more than quadrupled the official cost of the Abreu e Lima refinery to $18.5 billion in 2014 from $4 billion in 2008. Company officials, though, said the refinery will likely cost $20 billion by the time it is complete some time in the second half of 2015.
Petrobras said in its statement Friday it had sent an internal report on the refinery contracts to relevant authorities.
(Reporting by Caroline Stauffer; Editing by Jeb Blount and Bernadette Baum)