The 800-word story, which is set three years before Potter's birth, originally sold for 25,000 pounds ($32,152) at a 2008 charity auction. The item was stolen from a property in Birmingham between April 13th and 24th.
Local police issued a statement early Friday morning, seeking the keen eye of Potter fans who may stumble upon the item. "The only people who will buy this unique piece are true Harry Potter fans," investigating office PC Paul Jauncey said. "We are appealing to anyone who sees, or is offered this item for sale, to contact police."
Rowling retweeted the news report, adding, "Please don't buy this if you're offered it. Originally auctioned for @englishpen, the owner supported writers' freedoms by bidding for it."
The auction's proceeds benefitted two charitable organizations, English PEN and Dyslexia Action.
The untitled story, penned across both sides of an A5 postcard, features the character Sirius Black and Harry's father, James. It reportedly opens with the teenage Sirius and James cornered two by angry police officers after a high-speed motorcycle pursuit. The protagonists manage to escape using magic, and Rowling's final note reads, "From the prequel I am not working on – but that was fun!"
Rowling's cinematic Potter spin-off, Fantastic Beasts and Where to Find Them, premiered in November. The second installment of the planned five-part franchise – starring Jude Law Hogwarts headmaster Albus Dumbledore – will hit theaters on November 16th, 2018.