Hapless gem trader Kurt Kaiser lost out on a deal to sell a half million dollars worth of uncut diamonds, but really hit rock bottom when he despondently picked up a hooker — who took off with the gems.

“I woke and thought ‘I’ve been screwed,’ ” Kaiser, 47, told The Post yesterday outside his home in Forest Hills, Queens.

He believes he was drugged by the woman, who was last seen on a hotel surveillance video with his briefcase in one hand and her heels in the other.

Kaiser met the sexy brunette while throwing back drinks at Whiskey Park on Central Park South — his third stop Monday night after blowing a deal to sell the rocks.

“I was sitting by myself having a last vodka and soda, and she came up and asked, ‘Mind if I join you?’ I said: ‘Hell, yeah!’ ”

He spent another 45 minutes at the bar with the 23-year-old Hispanic woman, who wore a short, black dress and high heels.

Click here to read more on this report from the New York Post.