The phrase "an unknown from" is correct and usable in written English.
It can be used when referring to a person or thing that is not identified or recognized, often in contexts like discussions about individuals or sources.
Example: "The report was submitted by an unknown from the research department, raising questions about its credibility."
Alternatives: "an unidentified source" or "a stranger from".
Very much an unknown from Indiana.
The model was an unknown from Croydon called Kate Moss, and these images made her famous.
When Frida Giannini left in January this year, Allesandro Michele, an unknown from the design team, was elected.
"David was the first guy to produce me, to actually give me a chance," says Mark Morris, who turned up in 1981 as an unknown from Seattle and immediately entranced audiences.
For the less conventional parts -- Tom-Tom, Nora and Vern -- he chose Ted Bessell, an unknown from Queens who had studied at the Neighborhood Playhouse in New York; Ann Schuyler, a young actress who had worked with Mr. Tewksbury in Porterville; and Randy Boone, a 20-year-old folksinger whom Mr. Tewksbury discovered in a Newport Beach, Calif., coffeehouse.
Who needs fiction when Karlovic, an unknown from Croatia standing a lofty 6 feet 10 inches and ranked a lowly 203, can knock out Hewitt, the defending Wimbledon champion, who is seeded No. 1, on the very first day of the real tournament?
At present, the North receives virtually no food aid apart from an unknown amount from China.
One of the most romantic and superbly styled Hollywood movies, Max Ophüls's "Letter from an Unknown Woman," from 1948, is based on a book by Zweig.
The social welfare nonprofit received $25,000 in 2012 from Entergy Corp., $20,000 from Pacific Gas & Electric, $10,000 from Intel Corp. and an unknown amount from Google.
At the end of December 2012, a virologist successfully isolated an unknown virus from a clinical sample from a person in Japan who had died of unknown causes.
Contig 29 from SGFRm, coding for a protein similar to an "unknown" protein from R. h.
