Diddy's alleged after-hours exploits are set to be unearthed -- that is, if a new listing hyping up supposed BTS videos of him is to be believed, and more importantly ... purchased.

Here's the deal ... TMZ has been made aware of a listing on a crypto exchange site that went up by a person who purports to be in possession of a lot of Diddy footage over the years ... much of which, they claim, features him in some compromising situations.

Specifically, the listing touts itself as having "unreleased, never-before-seen private footage and photos of Diddy in his residence, private jet, studios and various other locations engaged in private activities ... and often doing and saying what appears to be very controversial things."

The listing claims to have video of Diddy partaking in what it describes as various dubious activities -- but stops short of suggesting anything he's currently under a microscope for.

In any case, the listing says any interested party can have access to this massive dump they claim to have -- which they say entails over 13,000 files and 3 terabytes of content -- for a price ... namely, about $1.5 million ... which is what they're hoping to sell it for.

Indeed ... all this alleged Diddy content is being hawked as an NFT -- and the listing says you can take it off their hands, and get access to the files, for a cool 425 wETH (Wrapped Etherium) which comes out to $1,494,032.25. That ... or the best offer they can field.

FWIW, there's no evidence that backs up the notion this is legit -- even though the listing claims it 100% is -- and so far, there are no offers for what they're selling. It just goes to show ... everyone is getting in on the Diddy feeding frenzy -- even in crypto land.

Of course, the backdrop to all this is the fact that Diddy got raided on both coasts this week by the feds -- this as he's become the target of a federal investigation that's looking into various claims. He's denied any wrongdoing, and he also hasn't been charged with a crime.

We've reached out to Diddy's team ... so far, no word back.