Critics of animal research released internal records Monday detailing a questionable study at the University of Wisconsin.
Primate Freedom Project said the study led to an "unusual number" of deaths and illnesses of rhesus monkeys in 2001 and 2002.
The UW memos uncovered by the group show one of the monkeys died while an attendant went out to lunch during an experiment, and others were given drugs that had not been approved by a review committee.
Critics said such cruel and sloppy research methods must be stopped at UW Madison's National Primate Research Center, one of eight federally funded centers to study primates.
University officials said the memos show that the school took punitive action against Ei Terasawa, a professor of pediatrics, after problems with her research on monkeys' brains surfaced in 2003.