PARIS (AFP) - Ms Carla Bruni said the charges faced by her husband and former French president Nicolas Sarkozy in connection with a probe into illegal party funding were "painful" for her and her family, according to local media on Wednesday.

"It's painful to talk about it and equally painful to not talk about it.

It's painful for the family," the singer said, wiping away a tear, in an interview with Le Parisien published on Wednesday.

But the one-time first lady and former model said her husband was feeling "serene and combative" after he was charged on Thursday with taking advantage of France's richest woman, Ms Liliane Bettencourt, when she was weakened by ill health.

The decision came after Mr Sarkozy was summoned for face-to-face encounters with former members of Ms Bettencourt's staff, including her butler, in an investigation into allegations he accepted envelopes stuffed with cash from the elderly L'Oreal heiress to fund his 2007 election campaign.

Ms Bruni told Le Parisien: "It's unthinkable to imagine that a man like him could take advantage of the weakness of a woman the same age as his mother."

Investigators suspect up to 4 million euros (S$6.4 million) of Ms Bettencourt's cash made its way into the coffers of Mr Sarkozy's UMP party.

Ms Bettencourt is now 90 and has been incapacitated since 2006, according to doctors.

On Monday, Mr Sarkozy used his Facebook page to insist the charges against him were "unfair and unfounded".

If convicted, Mr Sarkozy could face up to three years in jail, a fine of 375,000 euros, and a five-year ban from public office.