Khloe Kardashian Recalls Running Into Justin Bieber At Diddy's Bash, Resurfaced Clip

A resurfaced clip from "Keeping Up With The Kardashians" is raising eyebrows ... with Khloe Kardashian spilling the tea about attending one of Diddy’s notorious parties, casually name-dropping that Justin Bieber was also in the mix.

In the clip from 2014, Khloe told sister Kourtney, "I got on a plane at 5:30 AM. Well, this party ... I think half the people there were butt-naked ... You would have loved it!"

When Kourtney asked who was with her, Khloe casually rattled off the guest list ... mentioning she was with a bunch of pals -- Diddy, Quincy, and Bieber, who was 20 at the time.

This isn't the only video drawing concerns given the serious crimes tied to these infamous bashes ... there have also been several other resurfaced vids of a teenage Bieber hanging out with Diddy, getting fans worried online.

Bieber has yet to speak out on the matter -- but apparently, JB is well aware of all the allegations swirling around Diddy ... a source close to him has told PEOPLE he’s choosing to focus on his wife Hailey and their young son, Jack Blues, instead.

As we reported ... Diddy was arrested in NYC by federal agents and hit with charges including sex trafficking, racketeering conspiracy, and transporting people for prostitution, among other serious offenses.