David Copperfield - Cleared in Rape Investigation

David Copperfield is in the clear in the two-year investigation over alleged rape ... federal prosecutors have decided to drop the case without filing charges.

The woman who lodged the complaint -- a former Miss Washington contestant -- said in a civil lawsuit she was in the audience for a Copperfield performance when David spotted her and invited her to his private island in the Bahamas in 2007.

The woman claimed Copperfield sexually assaulted her on the island.

Copperfield's lawyers called the woman's lawsuit, "extortion for money, plain and simple."