The Food and Drug Administration (FDA) announced Friday it is ending the controversial nicotine addiction experiment it had been conducting on squirrel monkeys following an outcry from consumer and animal advocates.

In a statement, FDA Commissioner Scott Gottlieb said the agency is permanently ending the study, in which adult and adolescent squirrel monkeys were injected with nicotine, and placing the animals in a permanent sanctuary home.

Gottlieb suspended the study in the fall and called for an investigation into the welfare of the animals after learning that four monkeys had died.

On Friday, Gottlieb said based on the investigation's findings, it is clear the study was not consistent with the agency's high animal welfare standards.

A team of primate veterinarians and animal-care professionals, he said, found repeated deficiencies with the agency's third-party animal welfare contractor and a lack of oversight.

In a letter to Gottlieb in September, world-renowned primatologist Jane Goodall called the FDA's study "shameful" and urged the agency to end its research project.

"Not only is it extremely cruel to restrain monkeys, but the ill-effects of the nicotine, apparently recorded on video and documented, are said to include vomiting, diarrhea and tremors," she wrote. "I was especially horrified to read that during the course of the experiments, each monkey is locked alone in a cage for nearly three years. For such social and intelligent animals this, together with the horrific experiments themselves, is tantamount to taxpayer-funded torture."

Consumer Advocates for Smoke-Free Alternatives Association, Students for Sensible Drug Policy and Not Blowing Smoke also urged Gottlieb in a letter earlier this month not to resume the studies.

"A nonhuman animal that does not choose to smoke and is forced to live in a controlled, sterile and highly stressful captive environment is incredibly unlikely to adequately inform questions about the complex behavior of human smokers who have considerably more complex brain functioning and live in a much more complex world," they wrote. "We consider the use of animals in studies putatively designed to inform tobacco policy to be misguided, unreliable and unethical."

Gottlieb said he's called for an independent, third-party investigation of the agency's animal research programs, starting with those conducted at the FDA's National Center for Toxicological Research, and has created a new Animal Welfare Council to provide centralized oversight of all animal research activities and facilities under the agency's purview.

While the agency is working to reduce the need for animal testing, Gottlieb said there are many areas where animal testing is still needed.

"Without animal research, it would be impossible to gain some of the important knowledge needed to prevent human and animal suffering for many life-threatening diseases," he said. "In the past, animal research has played a critical role in vital health advancements such as preventing polio, eradicating smallpox and identifying new cancer treatments."

Anthony Bellotti, president and founder of the taxpayer watchdog group White Coat Waste Project, praised FDA for it's decision in a statement Friday.

"This is a big victory for taxpayers and abused animals and it's a step in the right direction for government transparency about secretive and wasteful spending," he said.