The company indicated that an ethical alert was sounded some time before May 1 last year and the executives were suspended after the company carried out investigations.
The company has not yet concluded whether there was actual "wrongdoing" on the part of the employees in question, though an unnamed source told Reuters the three were "caught red-handed."
Reports indicate that one of the executives may be as highly ranked as a member of Renault's management committee while the other two were believed to be managers.
It appears that the company is concerned that the leaked technology may have found its way to a new player from an emerging economy. China has made it clear that they want to be the dominant player in the electric vehicle race.
Mitsubishi had converted one of their i compact cars into an electric vehicle and it immediately became the best selling electric car in the world.
The launch of the Leaf took the industry by surprise as Nissan had stayed well below the radar for electric car production plans and preceded those from companies such as Tesla which has been hyping their electric offerings for years.
The Financial Times estimated that Renault Nissan may have invested as much as USD5 billion into electric technology.
The Leaf has an initial production run of 20,000 vehicles, all of which have been snapped up. The Leaf is now the most popular electric car in the world
The Leaf has also earned the distinction of being the first electric car to be the official vehicle of a head of state when the President of Portugal chose it for his official transport.
Renault CEO Carlos Ghosn has frequently predicted that electric vehicles will represent 10 percent of global production by 2020, a number considered audaciously high by most industry analysts.
With annual global car production set to reach around 75 million by that time, electric cars will be a major sight if Ghosn is correct in his prediction.
Between them, Renault and Nissan plan to launch eight separate electric cars over the next four years, including Renault's Fluence ZE electric midsize sedan.