Billionaire Kirk Kerkorian -- Allegedly Held Captive

Kirk Kerkorian -- the billionaire mogul who once owned the MGM Hotel in Las Vegas and United Artists -- is MIA, in dire shape and needs court protection from those who are holding him hostage -- this according to allegations in new legal docs.

The 95-year-old Kerkorian hasn't been seen in public since June, 2012, according to his ex-wife and the mother of his 15-year-old daughter, Kira. The ex, Lisa Kerkorian, claims in legal docs the managers of Kerkorian's company, Tracinda Corp, have been controlling him and keeping him from his daughter for the last 5 years.

And get this ... according to the docs, Kerkorian was a fixture for years at the legendary Polo Lounge at the Beverly Hills Hotel -- in fact, the Polo Lounge kept a table specifically for Kirk, but the table hasn't been occupied for months.

Lisa says their daughter hasn't had any contact with Kirk since 2008 and all attempted communications were thwarted by Kirk's handlers.

Lisa and Kirk were possibly in the nastiest celebrity divorce in Hollywood history, yet now Lisa has gone to court on behalf of her daughter to seek the appointment of a conservator to manage Kirk's affairs and pave the way to re-establish a relationship between Kirk and Kira.

The legal docs make it clear -- Lisa feels Kirk could be at death's door and Kira wants to see him before he passes.

And one more twist ... Kira isn't even Kirk's biological daughter, but he raised her as his own.