Court documents regarding search were sealed, and authorities said only that the Alpha Delta house raid Thursday was part of a two-year investigation.
Police removed 10 crates and two bags of evidence, along with two sledgehammers, a videotape and a computer, according to the Valley News of Lebanon.
George Ostler, lawyer for the fraternity members, declined to comment except to call the search a "major interruption."
Police Chief Nick Giaccone wouldn't comment on the investigation except to say that drugs are not the focus and that more arrests are expected. A 19-year-old student was arrested at the house on a drug charge, but police it wasn't related to the investigation.
William Walker, vice president for public affairs at Dartmouth, said in a statement that the school was cooperating with the investigation.
"National Lampoon's Animal House," starring John Belushi, portrayed college fraternity debauchery. One of the writers, Chris Miller, was a 1964 Dartmouth graduate and a member of Alpha Delta.