I personally think it is worth investigating these allegations
And you hit the nail on the head about why an elected representative won’t say one way or the other unless it’s objectively proven or shown to be false - anything else doesn’t need a response. Further any rep who does claim the matter to have been solved, one way or the other, only opens themselves up to criticism for something they probably didn’t get into politics for in the first place.
When scientists and experts (plural) start getting involved then it’s interesting however, imo, your focus on government being the ultimate truth-finder is flawed