The French prosecutor is to appeal against the decision to clear Dominique de Villepin of any wrongdoing in the Clearstream affair.
The former French prime minister was found not guilty on all four counts yesterday of plotting to discredit Nicolas Sarkozy over alleged bribes paid into an illegal bank account.
He had been charged with complicity to slander, to use forgeries, dealing in stolen property and breach of trust.
De Villepin had been accused of failing to intervene in the corruption inquiry despite knowing that claims against Sarkozy were false.
Paris prosecutor Jean-Claude Morin had requested an 18-month suspended jail term and a 45,000 euro fine be levied against de Villepin.
In a radio interview this morning he said he believed not all the facts relating to the case have emerged.