Hmm. I don't believe it. The "alien spaceship" theory was invented in late-40s by Alexander Kazantsev, Soviet sci-fi writer. He also said that Tunguska explosion was nuclear.
There are many theories about that catastrophe, the most common is a small comet explosion, that explains the absence of any meteorite particles. My favourite explaination is the natural gas fuel-air explosion from a crack to gas layer. I explains almost everything - including a supersonic explosion wave from a place where gas was ignited to main expolsion site that could look like a falling meteorite. Just imagine natural gas being blown from a crack by the wind until it reached some place where it was ignited...
BTW, there is nothing about it in today's Russian news.
