We uncovered the mystery graffiti artist tagging Anna Delvey’s door

That “mystery graffiti artist” tagging Anna Delvey’s building isn’t a mystery anymore.

After Page Six ran a story this week about an unknown tagger who keeps painting “Anna!” outside the building where the fake German heiress is under house arrest — a tipster identified the street artist for us.

She goes by the handle, “Anna!”

Delvey’s rep had told us of the paint, “Someone keeps doing it ever since she moved there. They’ve painted over it, and someone comes back and does it again. We have no idea who.”

We’ve also learned that Delvey is aware of “Anna!” the artist — but it’s unclear if they actually know each other already. (Could it all be, gasp, an attention seeking stunt? Who’s to say?)

When we followed up with questions for Delvey’s rep after learning about “Anna!” through a keen-eyed tipster, Delvey’s rep conceded, “Anna knows of [Anna!], but they haven’t met.”

Delvey apparently thought she might know who was tagging her door as well, we hear.

According to a web site for “Anna!,” real identity unknown, she is “known for her enigmatic works inspired by the streets of New York and its derelict underground spaces.”

The site adds that her work, “blurs the boundaries between light and darkness through her captivating portrayals of characters from stories and myths… her art is brimming with a complex duality, the essential tension between life and death.”

In other words, she writes “Anna!” on tall buildings and in subway tunnels. In one clip on her Instagram, she’s dressed as Alice in Wonderland and heads into the subway to tag.

In another Instagram picture the artist posted a collage of Delvey, Anna Nicole Smith and Anna Wintour with the hashtag, “AnnaGang.”

“Anna!” keeps her face hidden in photos.

She told the blog “Jet Set Times” that, “The name of the game is ‘no face no case.” She added, “my art is more than what I look like.”