La France Insoumise (LFI) leftist party's parliamentary group president Jean-Luc Melenchon in national parliament | Bertrand Guay/AFP via Getty Images Jean-Luc Mélenchon investigated for fraud: report Left-winger suspected of having paid former assistants with EU money.

French leftist Jean-Luc Mélenchon is being investigated for allegedly paying assistants with European Parliament money, the same charge leveled at Marine Le Pen, Le Parisien reported Tuesday.

According to the report, Mélenchon, who was an MEP from 2009 until being elected to the national parliament last month, is accused of having paid four of his former parliamentary assistants with EU money while they were carrying out working for his national party. Mélenchon, leader of the far-left movement France Unbowed, denies any wrongdoing.

The Paris prosecutor opened a preliminary investigation into "breach of trust" by 19 MEPs in March. On that list was former MEP Marielle de Sarnez, who resigned from her post as France's EU affairs minister after just a month in office.

National Front leader Le Pen is also accused of breaking the Parliament’s rules by having two assistants — Thierry Légier and Catherine Griset — carry out non-parliamentary work while being paid by the EU institution.

The investigation involving Mélenchon was launched following a claim from Sophie Montel, a National Front MEP, who sent a letter to French prosecutors and OLAF, the EU's anti-fraud office, about what she said were questionable activities.