The FBI are reportedly still investigating the case although police official Laura Eimiller confirmed "the item was field tested with negative results."
"Khloe is fine," a source told E! News. "The studio has hired extra security. Khloe is heading to rehearsals right now. She is not worried."
According to the website, Eimiller confirmed the FBI, Los Angeles Fire Department and LA Police Department all responded to a report of the studio's "suspicious package" on Monday morning.
Fox reportedly declined comment regarding the white powder incident.
Similarly, Palin -- the 21-year-old reality TV star and daughter of 2008 Republican Vice-Presidential nominee Sarah Palin -- was sent a harmless yet suspicious package to the same location, where Dancing with the Stars is also taped, both during her time on Dancing with the Stars: All-Stars' current season and the show's eleventh edition in 2010.
Palin and her Dancing with the Stars partner Mark Ballas had also been receiving death threats during their stint on the show.