Arnie Klein Sings Like Canary -- I'll Tell You Where I Stashed the Artwork

He talked a big game ... but Arnie Klein folded like a cheap suit when authorities came banging on his door this morning ready to arrest him unless he told officials where to find his expensive (missing) art collection ... TMZ has learned.

We broke the story ... a warrant was issued for Klein's arrest after he allegedly failed to turn over more than 100 pieces of wildly expensive artwork as well as a 2001 Ferrari Spider to the bankruptcy trustee after he filed for bankruptcy in 2011.

A rep for the U.S. Marshals Service tells TMZ ... deputies went down to Klein's home in Palm Springs, CA to arrest him this morning ... when Klein suddenly felt the urge to spill his guts.

We're told ... Klein (Michael Jackson's former doctor) informed the deputies exactly where to find the art and the Ferrari -- so officials decided not to arrest him because they felt he was cooperative.

As for the artwork, it includes pieces by Andy Warhol (including the famous Marilyn Monroe), Robert Graham, David Hockney, Roy Lichtenstein, Claes Oldenburg, Renoir, Rodin and Toulouse-Lautrec.