The company: The shadowy history of a slick oil giant

Since Trafigura was founded 16 years ago, it has shot to a position of power in the murky world of trans-global oil trading where vast sums are made by cutting deals to buy and sell large quantities of "black gold" and shipping it around the globe in a fleet of chartered tankers.

With a turnover in 2008 of $73bn and 42 offices around the world, the privately-owned London-based company now ranks among the world's top three independent commodity traders. But its name has been linked to a series of scandals. The company was set up by a Frenchman, Claude Dauphin, and Dutch citizen Erick De Turkheim, who had both worked alongside Marc Rich, the oil trader who gained notoriety for his involvement in sanctions-busting deals in South Africa and Iran.

Mr Rich was wanted by the American authorities for allegations of tax evasion and business deals with Iran but was pardoned in controversial circumstances by President Bill Clinton.

There was no link between the Trafigura founders and Mr Rich's activities but the trading company got embroiled in its own sanctions-busting affair in 2001 when a Liberian-registered tanker it had chartered, Essex, was seized in 2001 by US Navy ships enforcing the "oil for food" programme in Iraq.

An investigation was launched into claims that the oil carried by the Essex was "topped off" with £4m of extra fuel destined for Saddam Hussein's regime. A Texas court named Trafigura in its investigations into sanctions-busting but Trafigura denied wrongdoing, claiming it had been misled by a French oil trading company, Ibex.

The managing director of Ibex claimed Trafigura had known about the illegal extra fuel and was trying to make good a loss incurred on an earlier Iraqi oil deal in 1999.

Trafigura's ability to spot a good deal is thought to be behind the dumping of tonnes of contaminated waste in Ivory Coast in 2006. Internal emails, obtained by Greenpeace, show it had sourced cargoes of "bloody cheap" Mexican gasoline in 2005 and 2006 which it intended to sell on for a vast profit by processing it elsewhere.

Initial efforts to clean the "coker gasoline" on land at a plant in the Tunisian port of La Skirra were abandoned, allegedly after port authorities raised concern about waste gases, and the process was continued on board one of Trafigura's chartered tankers, the Probo Koala, anchored off Gibraltar.

The deal appears to have worked until the company needed to get rid of the waste "slops" from the process. In Norway in 2007, an attempt to neutralise a similar kind of sludge to that dumped illegally in Ivory Coast led to an explosion, causing a large sulphur cloud.