'Million Dollar Listing' Star Matt Altman: I'm Getting Anti-Semitic Death Threats

9:00 PM PT -- A rep for Alex tells us Altman's allegations are "ridiculous" and "completely false," because Alex is Jewish ... and even had a Bar Mitzvah. The rep also scoffs at claims Alex is anti-semitic and homophobic, telling us he was an invited guest at the real estate reception, which he attended with his Jewish contractor and gay interior decorator.

A man who says he hates all Jews is threatening to kill Matt Altman from 'Million Dollar Listing' ... according to the docs filed by Matt.

Altman just requested and got a restraining order against Alex Khadavi, a famous L.A. dermatologist, who Matt says has been threatening him by phone and in person.

In the docs Matt says Khadavi walked up to him at a real estate event, and when Matt asked him to leave the private event ... Khadavi blurted out he "hated all Jews" ... and said he was going to kill Matt.

Matt says Khadavi's been making racist and homophobic comments by phone for years, but now that the guy's doing it face-to-face ... he needs protection.