A suppressed technology may be LENR (low energy nuclear reactions) / CF (cold fusion)
LENR/CF has been widely dismissed since the immediate aftermath of the Fleischmann & Pons announcement of cold fusion in 1989, and any positive results since then have generally been treated as a hoax by professional physics.
Cold fusion caused quite a splash in 1989, due to the prospect of clean abundant energy, so many researchers attempted to replicate - and everyone got negative results. Combined with no theoretical explanation for a phenomenon that appeared to contradict known physics, the consensus was that the initial finding was incorrect. No one knew how cold fusion could happen, and no one (besides the discoverers) could make it happen. After this, further research in the field was discouraged - it would look like a scam riding on public gullibility for a quick fix on energy issues, when everyone in professional physics knew there was nothing there.
But that is not the entire story.
The few researchers daring to work in this field have obtained consistent positive results which are repeated and replicated by other researchers. They determined the reason why everyone failed to replicate F&P, their experiment involved loading a substantial amount of deuterium (form of hydrogen) into palladium (a metal.) Replication over a range of experimental conditions determined that there is a critical threshold, if the ratio of deuterium to palladium is too low, no fusion occurs - but if the ratio exceeds this threshold, fusion is detected. F&P were unusually skilled at loading deuterium into palladium, and in retrospect (looking at how everyone ran their experiments) we see they achieved a higher ratio than anyone else at the time, so everyone else got negative results. The replications failed because a critical aspect of the experiment was not sufficiently documented by F&P and therefore not replicated by the other scientists, who were generally less skilled at working with these particular materials. (This detail may have been omitted because the authors were rushed into a quick publication, and they may not have known it was important if they hadn't run the experiment with a lower deuterium ratio.)
That explains why everyone seemed to get negative results after the initial discovery, putting cold fusion into the "not real" category in the public mind.
I wonder if the cabal suppressed this field. The few scientists there have gotten positive results - and understand why the initial replications failed - creating conditions where other researchers can replicate BOTH the successful cold fusion experiment by F&P and the negative experiments performed by other researchers. In science, it would be expected that this would spark replication efforts everywhere, and quick recognition that the phenomenon exists.
Especially with all the money dumped into clean energy. Someone should be able to get substantial funding to do this. But in practice, research is suppressed. Dr Hagelstein at MIT, one of the few active researchers, said that research efforts at MIT were actively opposed by the university, including extraordinary efforts to interfere with small quantities of research done on the side by some scientists, even breaking apart what was already underway. Moniz, department chair and Obama's future energy secretary, was reportedly involved. For a future secretary of energy to interfere with research into a suppressed form of energy seems interesting.
I assumed the block against LENR/CF was entrenched groupthink. But academia is one of the cabal's fortresses, so when academia behaves in this way in light of current knowledge, there may be more to it. Two strategic reasons for the cabal to block LENR/CF. First, clean low-cost energy - if the cabal thrives on resource scarcity and control, public awareness could be a threat. Second, the underlying physics is unknown, so maybe a theoretical explanation would open doors to other important advances in theoretical and applied physics.
Good sauce is a lecture series that Dr Hagelstein offers at MIT as part of IAP, a January non-credit session over which the administration has limited control, and professors teach what they want. Some of these lectures have been recorded and are available online. The full program is one week, and my understanding is that it provides a somewhat in-depth technical overview of what's currently known about the phenomenon, and critical commentary about how it is suppressed. He warns students that going into this field will end your professional career in physics.