(The short sells are on record to the investment king-pins. Their existence alone speaks volumes, so they wouldn't have to spread false rumors through other channels on top of that. The only way the SEC is going to prove a conspiracy is to prove they agreed in advance to flood the exchange, and influence the market, with short sells on Bear Stearns and Lehman. Seems hard to do, since they put their money where their "mouths" were.)

But to answer your question(?), yes Lehman reported it to the SEC and the SEC is investigating. We don't know the exact supporting facts.