LITTLE ROCK — The U.S. Food and Drug Administration has axed a nicotine addiction study at an Arkansas lab after the deaths of four squirrel monkeys.


The FDA issued a statement Friday saying the study was immediately put on hold in September when agency officials learned the four monkeys had died at the National Center for Toxicological Research. Three of the monkeys died because of complications involving anesthesia, and one death was related to bloat, the cause of which can be unclear, said Tara Rabin, an FDA spokeswoman. Rabin said she didn’t know when the monkeys died.


The study began in 2014 with two dozen male monkeys, half adults and half adolescents, according to documents on the FDA’s website.


Renowned primate researcher Jane Goodall wrote to the agency Sept. 7, saying the center’s treatment of monkeys was “tantamount to taxpayer-funded torture.”


“I was disturbed — and quite honestly shocked — to learn that the U.S. FDA is still, in 2017, performing cruel and unnecessary nicotine addiction experiments on monkeys,” Goodall wrote.


She said devices were placed in young monkeys to deliver nicotine directly into their bloodstreams. The animals were then put in restraint devices and trained to press levers to receive nicotine doses, Goodall wrote.


“To continue performing nicotine experiments on monkeys when the results of smoking are well-known in humans — whose smoking habits can be studied directly — is shameful,” she wrote.


An investigation of the lab found there was “a generalized lack of adequate oversight” that could lead to future problems, said Scott Gottlieb, FDA commissioner.


“Based on this (FDA) team’s findings, it is clear the study was not consistent with the agency’s high animal welfare standards,” Gottlieb said Friday. “These findings indicate that FDA’s animal program may need to be strengthened in some important areas.”


Gottlieb has called for a third-party investigation of all of the agency’s animal research programs, beginning with those conducted at the Arkansas lab. He said the remaining monkeys at the facility will be placed in a new permanent sanctuary home.