Around 100 preserved brains, belonging to former inmates of a lunatic asylum, have "gone missing" from the University of Texas, baffling scientists.
The organs had been kept in the animal resources centre in a basement for the past 28 years, and were being kept on the premises temporarily, Sky News reported.
One of the missing brains is believed to have been that of mass murder Charles Whitman, who killed 16 people, including his mother and wife, during a gun rampage in 1966.
"We think somebody may have taken the brains, but we don't know at all for sure," co-curator psychology Professor Tim Schallert told the Austin American-Statesman.
Schallert's colleague and co-curator, psychology professor Lawrence Cormack, added: "It's entirely possible word got around among undergraduates and people started swiping them for living rooms or Halloween pranks.
"They are no longer in the basement."
The university says it will investigate the circumstances surrounding the collection, which is used as a teaching tool.