Tech billionaire Elon Musk's brain-chip company Neuralink is reportedly facing a legal challenge from an animal rights group that has accused the company of subjecting monkeys to "extreme suffering" during years of gruesome experiments.

Neuralink's brain chips were implanted in monkeys' brains during a series of tests at the University of California, Davis from 2017 to 2020, according to a compliant from the Physicians Committee for Responsible Medicine filed with the US Department of Agriculture.

The monkey was later killed during a "terminal procedure," the group said in a copy of the complaint shared with The Post.

In another case, a monkey had holes drilled in its skull and electrodes implanted into its brain, then allegedly developed a bloody skin infection and had to be euthanized, according to the complaint.

Days later, researchers wrote that the animal "appeared to collapse from exhaustion/fatigue" and was subsequently euthanized.

The experiments involved 23 monkeys in all.

At least 15 of them died or were euthanized by 2020, according to the group, which based the report on records released through California's open records law.

Musk claims that Neuralink's brain chips will one day make humans hyper-intelligent and let paralyzed people walk again.

(This story was published from a syndicated feed. Only the headline and picture have been edited by FIT.)