French President Nicolas Sarkozy's has denied new claims that he took undeclared campaign cash from the heiress to the L'Oreal cosmetics fortune five years ago, just as the race for next year's presidential elections is heating up.
Mr Sarkozy's allies suggested the accusations are a campaign ploy against the unpopular president. Similar accusations first surfaced last year.
Still, questions about how Mr Sarkozy financed his 2007 campaign could hit his likely bid for re-election in April and May. Critics have long deemed the conservative leader was too cosy with the rich, criticism that carries particular sting now that the French economy is stalling and many of his supporters are disillusioned with his leadership.
The leader of France's main opposition party, Socialist Martine Aubry, called for a new investigation into whether Mr Sarkozy received illegal campaign cash from Liliane Bettencourt, Europe's richest woman.
An accountant for Ms Bettencourt said a year ago that she gave 50,000 euros(£44,000) in cash in 2007 to Mr Sarkozy's party treasurer for the presidential campaign - well beyond the legal limit on individual donations. The accusations surfaced during a series of investigations into the heiress' finances.
A book being released on Thursday suggests that Mr Sarkozy himself received undeclared campaign money.
The book, "Sarko m'a tuer" ("Sarko killed me"), quotes investigating judge Isabelle Prevost-Desprez as saying a witness she questioned "told me that he had seen cash handed over to Sarko," a nickname used for Mr Sarkozy.
Ms Prevost-Desprez says, however, that the comment came outside the formal questioning and was not recorded in judicial documents.
Ms Prevost-Desprez was later taken off the case. The book quotes her as saying she came under political pressure and that witnesses were afraid of testifying because the case is so sensitive for Mr Sarkozy.
Mr Sarkozy's office called the claim "scandalous, unfounded and untrue."