Renault warned that the automaker's strategic assets were at risk in suspected industrial espionage involving the automaker's flagship electric vehicle program.
A senior executive at the French automaker said the matter concerned people in "extremely strategic" positions.
"The investigation, which lasted several months, enabled us to identify a body of converging evidence demonstrating that three Group employees have committed misconduct that infringes Renault's ethics, consciously and deliberately endangering the company's assets," Christian Husson, General Counsel and Compliance Officer of Renault said in a statement on Thursday.
Renault has suspended three executives including a management committee member and two others suspected of leaking electric-car secrets.
The highest ranking of the three suspended executives is Michel Balthazard, vice president for advance engineering and a member of the management committee, two people with knowledge of the matter told Bloomberg News.
Renault is worried that its electric vehicle program, in which Renault with its partner Nissan is investing 4 billion euros ($5.3 billion), might be threatened.
Renault's new strategic plan, due to be unveiled in February, is expected to focus strongly on electric vehicles, as well as synergies with Nissan and emerging market growth.
French industry minister Eric Besson told journalists on Thursday he believed the matter was related to electric vehicles, adding he had taken early steps to step up protection.
"I have asked the economy ministry administration ... to strengthen the requirements for protection of companies that ask for state aid and financial contributions for innovation," he said.
Besson earlier told RTL radio the matter was serious: "It illustrates once again the risks our companies face in terms of industrial espionage and economic intelligence, as we call it today." The French state owns a 15 percent stake in Renault.
Two sources told Reuters the suspended employees could be dismissed soon if they are found to have leaked information.
"The internal investigation is continuing, but a decision should be made in the coming days," said one source close to the company. "In nine out of 10 cases, suspension (without pay) of this kind, is followed by a dismissal," he said.