This article is more than 1 year old

This article is more than 1 year old

Commodity traders Glencore, Vitol and Trafigura are under investigation on suspicion of paying more than $15m (£11.7m) of bribes to the Brazilian state oil firm Petrobras, opening a fresh chapter in the Car Wash investigation that has rocked the country’s establishment.

Federal police in Brazil said they had been examining allegedly corrupt fuel trades involving Petrobras, the national oil company that has been at the centre of the Car Wash affair.

The investigation has already led to the imprisonment of one former president, as well as some of the country’s most prominent business figures.

Operation Car Wash: The biggest corruption scandal ever? Read more

Glencore, Vitol and Trafigura, all of which have strong ties to London, are the subject of the next phase of the Car Wash investigation, according to federal authorities in Brazil.

It comes a month after the Guardian questioned the three firms about a report by the campaign group Global Witness that called for enforcement bodies in the UK and the US to investigate the companies’ connections to business people named in the corruption scandal.

Police said they were looking into suspected bribery of Petrobras officials, amounting to more than $15m and linked to more than 160 fuel trading deals between 2011 and 2014.

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They alleged that Petrobras officials had arranged fuel trades at prices that differed from the market rate, pocketing the difference, which they referred to as the “delta”.

The prosecutor Athayde Ribeiro Costa referred to a “criminal scheme practised over years with the involvement of large international trading companies, some of them with revenue larger than Petrobras.

“It’s in the interest of civil society to know of the full extent of this scheme and recover the money that’s been diverted. As at the beginning of Lava Jato [Car Wash], this opens opportunities for the collaboration of defendants and companies to come forward.” He said prosecutors had been inundated with more offers to cooperate than they could handle.

Global Witness highlighted potential links between the companies and the Car Wash scandal last month in a report titled Friends in Low Places. A spokesperson for the campaign group reiterated its calls for enforcement agencies in the US and UK to launch their own investigations.

He said the naming of the companies by Car Wash prosecutors was a “wake-up call to prosecuting authorities in all relevant jurisdictions – including the US, UK and Switzerland, where the companies have major offices. These countries should fully support Brazil, and move to clean up the world’s oil business.”

A 190-strong team of police in Rio de Janeiro and the state of Paraná have issued 37 judicial orders, 26 search warrants, 11 pre-trial arrest warrants and six subpoenas.

Glencore declined to comment. Trafigura said it did not comment on legal matters.

Vitol said it had a “zero-tolerance policy in respect of bribery and corruption”, adding: “Vitol will always cooperate fully with the relevant authorities in any jurisdiction in which it operates.”