Franca - Police have carried out searches of the home and offices of former French President Nicolas Sarkozy as part of a campaign financing probe.

  A law firm in which Mr Sarkozy owns shares was also searched, reports say.

  The investigation is related to allegations that Mr Sarkozy's 2007 presidential election campaign received illegal donations from France's richest woman, Liliane Bettencourt.

  Mr Sarkozy has previously denied all wrongdoing.

He is currently in Canada with his family, his lawyer, Thierry Herzog, told the AFP news agency.

In presidential elections in May, Mr Sarkozy lost to Socialist challenger Francois Hollande, and his presidential immunity from prosecution ended on 16 June.

   Tens of thousands of euros were allegedly funnelled to Mr Sarkozy's campaign by Ms Bettencourt's office.

It is not so much the investigation; we have known for some time that magistrates were looking closely at the affairs of the last president and how his 2007 campaign was funded. What is far more significant is the speed with which Tuesday's operation was mounted.

Nicolas Sarkozy lost the cloak of presidential immunity on 16 June and within a month his home and offices have been raided, seemingly without warning.

We don't know what was taken but it seems clear now that on the basis of witness evidence gathered, the financial crimes unit is looking for a "smoking gun". Mr Sarkozy has vehemently denied there is one to find. But then so did his predecessor!

It took the French authorities five years to catch up with former President Jacques Chirac. But in December, after a long running investigation - and no end of attempts by Mr Chirac to avoid justice - he was found guilty and handed a two-year suspended sentence for corruption.

 There was criticism for years that Mr Chirac had been shown favourable treatment. That is plainly not the case with Mr Sarkozy.

This operation may have uncovered nothing in material evidence but there is no escaping the symbolism. And this won't be the first or the last time Mr Sarkozy faces embarrassing questions over influence and campaign funding.

   Individual campaign contributions in France are limited to 4,600 euros ($5,800).

   "These raids... will as expected prove futile," Mr Herzog said in a statement.