LAPD DROP JAY Z'S EXTORTION INVESTIGATION

the rapper's camp is no longer pursuing criminal extortion charges over $20 million worth of Jay Z songs ... and the Beverly Hills PD has closed its investigation as a result.

 last month after Jay's people accused him of stealing the master recordings for several big Hova songs back in 2002 -- and then trying to hold them ransom ... for a $100,000 "storage fee."

LAPD confiscated the recordings pending the result of a criminal investigation, but law enforcement sources now tell us, Jay Z's camp has decided NOT to pursue extortion charges. As a result, BHPD will no longer be investigating. Case closed.

But the tale of the tapes isn't over -- we're told the LAPD -- which took possession of the tapes a few weeks ago -- will continue to hold on to the recordings until a civil judge tells them to do otherwise.

Now here's Solange punching Jay Z again.