Police have carried out searches of the home and offices of former French President Nicolas Sarkozy as part of a campaign financing probe. The detectives investigating alleged illegal campaign-financing by L'Oreal heir Liliane Bettencourt, France's wealthiest woman searched Carla Bruni's Paris mansion in which she lived with her husband since thier marriage in 2008. They also searched a law firm in which Mr Sarkozy owns shares, reports say.

This investigation is related to allegations that Mr Sarkozy's 2007 presidential election campaign received illegal donations from Liliane Bettencourt. Mr Sarkozy has previously denied all wrongdoing.

The family is currently in Quebec, Canada and were not present at the residence, his lawyer Thierry Herzog told the AFP news agency. In presidential elections in May, Mr Sarkozy lost to Socialist challenger Francois Hollande, and lost his immunity from prosecution on June 16th.

Tens of thousands of euros were allegedly funnelled to Mr Sarkozy's campaign by Ms Bettencourt's office. Individual campaign contributions in France are limited to 4,600 euros ($5,800).

The investigation is part of the wider Bettencourt saga, which has gripped France for years with plot twists including a disgruntled butler who hid a tape recorder in the drawing room and, crucially, whether security services at the head of the French state may have spied on journalists to hush it all up.

Sarkozy could also become a focus of a separate investigation into whether or not there was a shady cabinet noir at the highest reaches of the French government, which used the secret services to spy on journalists at Le Monde to uncover their sources for stories about the Bettencourt affair.

A security chief and Sarkozy ally has been placed under investigation in the alleged political spying scandal. Sarkozy has denied any involvement.