The conviction of senior executives in a bribery at oil giant Elf Aquitaine is just part of a much wider investigation into an alleged network of illegal lobbying and suspected bribery.

The system may have been sanctioned by France's political and business elite in the late 1980s and early 1990s, when the late President Francois Mitterrand was in office.

A subtle game of shadows and light Roland Dumas on French lobbying efforts

Roland Dumas, the 78-year-old former foreign minister, was initially found guilty of illegally receiving funds from Elf Aquitaine between 1989 and 1992 - but was cleared on appeal of all charges.

Other top Elf executives, however, were convicted.

The trial focused specifically on allegations of corruption arising from the $9m which Elf is said to have paid to Christine Deviers-Joncour, the former mistress of Mr Dumas, for her work as a consultant and lobbyist in support of the firm's world-wide sales effort.

Lavish lifestyles

Mr Dumas has said he played a part, for the sake of France, in what he called "a subtle game of shadows and light", but denied that he made any personal gain.

The trial produced more headline-grabbing details about the lavish lifestyles of the accused, and the many gifts allegedly given to Mr Dumas in an attempt to influence government decisions.

Mr Dumas denied personal gain

They included custom-made boots costing $1,500 and antique Greek statuettes worth more than $40,000.

But the case is only a prelude to a much wider criminal investigation, which seeks to expose a politically explosive story.

It is one of suspected bribery on a huge scale by Elf executives, who managed a sophisticated lobbying network on behalf of other French firms.

Among the allegations are that:-

• Illegal payments were made to ensure the $2bn sale of six warships to Taiwan by another French state-owned business group, Thomson-CSF.
• During the term of office of the late socialist President, Francois Mitterrand, illicit commissions were paid on other business deals for French companies in Africa, Latin America and Europe.
• Bribes or backhanders were made to the German Christian Democratic Union, the party headed by former Chancellor Helmut Kohl, in 1992. At that time Elf took over one of the biggest businesses in eastern Germany, the Leuna oil refinery and its network of petrol stations, as part of the wholesale privatisation of former East German state assets.

Mr Kohl was investigated for managing illegal party funds, but he refused to name the donors, in open breach of German laws on party funding.

Secret bank accounts

Mr Kohl also denies that illicit donations from the French Government related to the Leuna deal went into his network of secret bank accounts holding the "slush funds" which he says he used to help selected local branches of his own party.

So far prosecutors in Germany have been unable to substantiate any serious charges against the former leader. Revelations from Paris could give them fresh ammunition.

To many observers such allegations are not even remarkable.

The French press has portrayed the whole story as a glimpse into a world of secret influence-peddling and backhanders where the letter of the law traditionally played little part.

Ethics on trial

Elf itself has been taken over since these events took place by the private sector firm, Total Fina Elf.

But in effect, French business ethics are on trial, and the ripples may spread far and wide. At stake are the reputations of many of the great and the good of European politics 10 years ago, including former German Chancellor Kohl and the late President Mitterrand.

And guilty verdicts stir up old arguments between Europeans and Americans about business ethics.

Industrial spying

Some US officials have sought to justify the use of the sophisticated Anglo-American eavesdropping system known as Echelon on the grounds that it has provided evidence of unfair business practices - a code word for bribery - by rival French firms in big business deals.

Against that, some members of the European parliament have claimed the Echelon system, which can intercept communications across Europe, is being unfairly used as a tool of US industrial spying.

Mr Dumas declared that he would refuse to be play the role of scapegoat for what he says he did for France. In the end, the courts agreed with him. But the Dumas trial set in motion a judicial process which could yet bring unsuspected casualties.