DC Dave's "Seventeen Techniques for Truth Suppression" are a good analytical tool for understanding what's happening when governments are embarrassed by revelations of corruption and criminality and get to spinning, a kind of Spicer-Conway masterclass (albeit one that's spoiled by its descent into conspiracy theory with the Vince Foster suicide as an example of such truth-suppression).
1. Dummy up. If it's not reported, if it's not news, it didn't happen.
2. Wax indignant. This is also known as the "How dare you?" gambit.
3. Characterize the charges as "rumors" or, better yet, "wild rumors." If, in spite of the news blackout, the public is still able to learn about the suspicious facts, it can only be through "rumors." (If they tend to believe the "rumors" it must be because they are simply "paranoid" or "hysterical.")
4. Knock down straw men. Deal only with the weakest aspects of the weakest charges. Even better, create your own straw men. Make up wild rumors (or plant false stories) and give them lead play when you appear to debunk all the charges, real and fanciful alike.
5. Call the skeptics names like "conspiracy theorist," "nutcase," "ranter," "kook," "crackpot," and, of course, "rumor monger." Be sure, too, to use heavily loaded verbs and adjectives when characterizing their charges and defending the "more reasonable" government and its defenders. You must then carefully avoid fair and open debate with any of the people you have thus maligned. For insurance, set up your own "skeptics" to shoot down.
6. Impugn motives. Attempt to marginalize the critics by suggesting strongly that they are not really interested in the truth but are simply pursuing a partisan political agenda or are out to make money (compared to over-compensated adherents to the government line who, presumably, are not).
7. Invoke authority. Here the controlled press and the sham opposition can be very useful.