Add Category
Thierry Legier and Catherine Griset are alleged to have been paid for non-existent jobs at the European Parliament.
The European Anti-Fraud Office (OLAF) said Le Pen, leader of the far-right Front National, initially admitted they had been paid while not working. She later denied having said so.
Le Pen was defiant when questioned about the investigation Wednesday on CNN affiliate BFM TV.
"If this situation amuses the magistrates," she said. "The thing I find the most surprising is that an investigating judge is supposed to be taking care of the case. Why is it necessary to lead another inquiry? Because this file is empty.
"The French know exactly how to tell the difference between real affairs and political cabals," she added.
Front National HQ searched
On Monday, the Front National confirmed a search had taken place at its headquarters.
"This is obviously an operation led by the media, whose only aim is to try and impair the proper functioning of the presidential campaign and harm Marine Le Pen's reputation," the party said in a statement.
"This is happening at the very moment when [Le Pen] is significantly gaining voting intentions, notably in the second round."
Le Pen, who has been a member of the European Parliament since 2004, has been asked to pay back a total of €340,000 ($357,000) but is refusing to do so.
"It's inadmissible. We have been persecuted by the EU Parliament. They are our adversaries," she said, adding that she had filed a complaint against the European Anti-Fraud Office.
Le Pen is fiercely Euroskeptic, and has promised to hold a referendum on France leaving the European Union if she is elected president.
CNN's Stephanie Halasz in London contributed to this story.