ABC bigwigs are going potty to find the identity of the leaker behind the Amy Robach tape — after the alleged source posted a letter online slamming the network under the name “Ignotus,” a wizard from the “Harry Potter” franchise.

After junior producer Ashley Bianco denied leaking the tape, on which the anchor complained that ABC News killed her interview with Jeffrey Epstein victim Virginia Roberts Giuffre, someone purporting to be the actual leaker and still working at the network posted a letter on Project Veritas blasting ABC’s “mission of seek and destroy” to conjure up the mysterious mole.

Project Veritas editors confirmed the missive was penned by the same ABC News insider who gave them the tape “in light of the actions taken against those wrongfully identified as involved in the leaking.”

An ABC insider said top execs were particularly puzzled by Ignotus. He is possibly best known as a Harry Potter character, a pure-blood wizard who has a cloak of invisibility, passed through generations, finally to Harry Potter. Ignotus also means “unknown” in Latin.

The ABC insider said, “They are freaking out over the Harry Potter reference. Does this mean the leaker is a Potter fan, likely one of the younger staff members who work the overnight shift? Or is the leaker citing Latin, which means he or she could be an older member of staff. I mean, how many young producers speak Latin these days?”

The source added ABC investigators have been rifling through staff emails and news logs and grilling staffers. The company has been isolating certain employees and putting them under pressure to turn on their colleagues in a bid to find the culprit, the source also claimed, adding that the investigation reports back up to the very highest levels of HR at ABC’s parent company, Disney.

Ignotus isn’t happy with the ABC probe either and under the header, “Why I, alone, released the Amy Robach Epstein tape,” he or she wrote, “I sit right here with you all in complete shock on how this has been handled….[the company] has spun into a mission of seek-and-destroy. Innocent people that have absolutely nothing to do with this are being hunted down as if we are all a sport.

“I challenge all of you to actually look inwards and remember why this company engages in journalism. We all hold the First Amendment at the foundation of this company, yet forget its history, its purpose, and its reasoning for even coming into existence to begin with. How lost we are… yearning to be found.

“I went to Project Veritas for the sole reason that any other media outlet else would have probably shelved this as well. I thank all of them … for seeking truth.”

Ignotus spookily added, “We are all human and mortal, creatures of mistakes and redemption. The road to redemption favors no soul.”

ABC reps declined repeated requests for comment, saying they could not discuss ongoing company investigations.