Fans think this photo proves Kylie Jenner has a secret third nipple.

The moon landing was faked. Aliens crashed to earth at Roswell. Elvis isn’t really dead. And Kylie Jenner has a secret third nipple.

Well, according to conspiracy theorists anyway.

The makeup mogul and reality TV star has social media ablaze with rumours she’s spent her entire public life covering up a rather prominent nipple on her knee.

(Hooray for 2017!)

It’s all because of this photograph uploaded to Instagram by the 19-year-old’s rapper boyfriend, Tyga.

A photo posted by Tyga / T-Raww (@kinggoldchains) on Jan 10, 2017 at 1:42pm PST

The picture has attracted more than 4,700 comments, the majority of which refer to the mysterious little blob.

"Just came to see the nipple on the knee of Kylie," wrote one fan.

"Lmao knee nipple!" added another.

There were other theories of course: "lady bug", "mole", "wart".

We're going to go ahead and assume it's a plant or some kind of decor that's out of shot, because...

1. There's a visible white stem of some kind.
2. That stem is casting a shadow.
3. And being one of the most famous, photographed (selfies included) women in the world would probably make it a teensie bit tricky to hide an extra nip on your knee cap.

Not convinced? Please browse these pictures of her nippleless knees as proof.

Case closed.