Before Chrysler co-president Jim Press took his position with the Michigan-based automaker last September, Press had spent the last 37 years of his career at Toyota. In fact, Press was the first non-Japanese executive to be inducted to Toyot's board of directors. But despite that close working relationship, Press and Toyota had a very different viewpoint of the goings-on at the Japanese automaker.

In a March 24th interview with Business Week, Press told the publication that "The Japanese government paid for 100 percent of the development of the battery and hybrid system that went into the Toyota Prius."

However, Toyota fired back at Press on Wednesday, saying that his allegations are untrue. "I can say 100 percent that Toyota received absolutely no support -- no money, no grants -- from the Japanese government for the development of the Prius," Toyota spokesman Paul Nolasco told The Detroit News.

While it's not uncommon for the for the Japanese government to fund private-sector projects, Press' allegations are the first that have accused Toyota of receiving funds from the Japanese government in the 10 year production run of the Prius.

If Toyota did in fact receive funding from the Japanese government, that would mean that the Japanese automaker had a huge advantage over U.S. automakers as they did not have the same kind of concessions from the U.S. government. However, since no one has ever heard or made these claims before, it seems a little hard to believe that Toyota would have received such funding -- which would have been worth at least tens of millions of dollars -- without anyone else knowing.

The Toyota Prius is the best-selling hybrid vehicle in the world and since its launch in 1997, Toyota has sold close to 1 million Prius vehicles worldwide.