Former French President Nicolas Sarkozy enters his car as he leaves his house in Paris, France, March 21, 2018. REUTERS/Benoit Tessier

PARIS (Reuters) - French investigators finished questioning Nicolas Sarkozy on Wednesday and judges are considering whether to open a formal investigation into allegations illegal campaign financing, a source close to the matter said.

Sarkozy was grilled for a second full day on Wednesday by police investigating allegations that his 2007 election campaign received funding from the late Libyan leader Muammar Gaddafi.

It is the second major investigation for Sarkozy, who is also facing charges of illicit campaign spending overruns during his failed re-election bid in 2012.