A former minister has been questioned over allegations that he took cash-stuffed envelopes from France's richest woman to illegally fund Nicolas Sarkozy's 2007 presidential bid.

The inquiry against Eric Woerth, a former budget minister and treasurer of Sarkozy's UMP party, comes as the president limbers up to seek re-election.

Woerth gave evidence before judges in Bordeaux, who are investigating alleged illegal donations by Liliane Bettencourt, 89, the L'Oréal heiress.

They were expected to place Woerth under investigation. Bettencourt's accountant, Claire Thibout, has said she handed over à50000 in cash to Patrice de Maistre, Bettencourt's wealth manager, whom she alleges passed it onto Woerth.

The bookkeeper told investigators she believed Maistre withdrew a further à100000 earmarked for Woerth from Bettencourt's bank accounts.

A court has since found that Bettencourt is suffering from dementia and Alzheimer's.

Woerth has denied any wrongdoing.