Former French President Nicolas Sarkozy is facing new legal charges over the alleged illegal financing of his  successful 2007 election campaign, according to financial prosecutors.

French prosecutors said that they had placed criminal conspiracy charges on Mr Sarkozy over claims he used Libyan funding for the campaign.

The charge for "membership in a criminal conspiracy" was brought on Monday, the prosecutors told AFP.

It adds to charges lodged in 2018 of "passive corruption," "benefiting from embezzled public funds" and "illegal campaign financing" for which Mr Sarkozy already faces trial.

Mr Sarkozy, who was president from 2007 to 2012, has denied any wrongdoing, saying on his Facebook page that his "innocence had been tarnished" by the charges, without "even the slightest proof".

Prosecutors suspect that Mr Sarkozy and his associates received millions of euro from the regime of former Muammar Gaddafi to help finance his election bid.

Mr Sarkozy, who claims he is the victim of a "plot" in this case, is the second former French president to stand trial after the late Jacques Chirac.