Stories like this have been circulating for years, they come in both Liberal and Conservative versions. The former is something like "evil corporate monopolies seek to strangle new technologies which would provide their expensive product or service at ridiculously low prices."
Actually, corporate monopolies would rather steal your idea and market it rather than squash it. The right-wing version usually has some noble entrepreneur victimized by an evil government bureaucracy. Heinlein's "Destination Moon" is based on this fantasy.The usual fuel conservation variant usually has something like a super carburetor than gives you a 100mpg, or some other similar violation of physical law.

I'm not saying that corporations or gov't agencies are nice guys, its just that they don't need guys in black suits and helicopters to resort to these tactics. That's why they have lawyers and lobbyists. For example, when Sarnoff got his version of FM radio broadcasting accepted over Armstrong's technically superior design, he did it by pulling strings at the FCC, not by breaking kneecaps. Battles like this are being fought all the time, there's one brewing now with cable and internet technologies.

As far as the technical breakthrough you mentioned (I must confess I gave your web link only the most cursory inspection) I am inclined to suspect that if this breakthrough does indeed exist, it is only a minor technical improvement not worthy of this kind of corporate skulduggery.
The true technological breakthroughs that do make a big difference usually don't sneak up on us, they are the result of research programs at large companies or big government labs. There's usually plenty of warning before these come, especially for us techies. We keep up with the news.

The major possible exception to this is in the field of computer hardware, where major technological leaps are often made by small, individual firms using clever variations of current techniques. But in fields like automobile power, there is only so much energy in fuel, and the laws of thermodynamics tell us how much will be lost out the tailpipe and the radiator. There just isn't that much room for dramatic improvements.

So no, I don't know for a fact if your story is plausible or not (and if I did all the research on the net I needed to do just to prove it I wouldn't have any time to post here). But my instincts tell me it's probably not true; I've been wrong before, but I've learned to trust my instincts.