I am not sure about all this: they did have a very competent secret service after all.

So the director of the agrar kolchose might lie and so on, but why should the secret informants who are installed in that company, lie about it?

So I am pretty sure, the information was avaiable. It was probably a matter of not wanting to believe the information as that would mean, the glorious sovjet union was maybe not so glorious after all - and thinking that, would make you a traitor. So lets just continue to wave and smile.