(NewsNation) — A medical ethics group is alleging in letters to the U.S. Securities Exchange and Commission that Elon Musk made false statements about the death of primates used for research at Neuralink, the biotech startup he founded, according to a WIRED report from earlier this week.

Musk on Sept 10 wrote in a reply on X, formerly known as Twitter that, “No monkey has died as a result of a Neuralink implant” and that “terminal moneys (sic)” who were close to death already were chosen for experiments.

Now, the Physicians Committee for Responsible Medicine, a nonprofit dedicated to ending live animal testing, wants the SEC to investigate these claims.

The committee alleges in the SEC letters that veterinary records show complications with implant procedures led to 12 “young, previously healthy” monkeys’ deaths. These records were also obtained by WIRED via a public records request, and the publication also interviewed a former Neuralink employee and researcher at the University of California, Davis primate center who “paint a wholly different picture of Neuralink’s animal research” than Musk described. (Neuralink’s experiments were done in collaboration with the staff of the California National Primate Research Center at UC Davis from September 2017 until 2020.)

Letters from the Physicians Committee for Responsible Medicine say Musk’s comments about the monkey’s deaths were misleading, and he knew them to be false.

“The animals’ deaths and the reasons for their deaths relate directly to the safety and marketability of the brain-computer interface Neuralink is developing, and thus it is critical that the company provide investors with factually accurate information,” the Physicians Committee for Responsible Medicine wrote to the SEC. In the letter, physicians argue that with 156.4 million followers on X, formerly known as Twitter, Musk’s reach is “immense and affects the perception of Neuralink by the general public and potential investors.”

NewsNation has reached out to Neuralink and the SEC for comment.

According to WIRED, Musk promised that Neuralink would engineer an implant allowing human brains to communicate wirelessly with artificial devices and even each other. After its founding, the company acquired a large number of animal subjects to test these implants.

UC Davis veterinary records show that surgically putting these implants into monkey brains caused a number of complications including bloody diarrhea, partial paralysis and cerebral edema, or “brain swelling.”

One example noted by WIRED was an experimental surgery in December 2019, where an internal piece of an implant “broke off” in a monkey’s brain.

Researchers observed the monkey, a 7-year-old rhesus macaque, scratching at the surgical site, causing a bloody discharge. The monkey yanked on a connector and dislodged part of the device. Despite a surgery to repair the issue the next day, fungal and bacterial infections took root that were deemed unlikely to be cleared, in part because the implant covered the infected area. That monkey ended up being euthanized on Jan. 6,, 2020.

Another female monkey researchers identified as “Animal 15” died in March 2019. Animal 15 would press her head against the floor in the days after her implant surgery, which records said was a symptom of pain or infection.

Eventually, the 6-year-old female rhesus macaque began to lose coordination and would shake uncontrollably when she saw lab staff. Before her euthanization, WIRED reports, the monkey’s condition deteriorated for months. There was bleeding in Animal 15’s brain, a necropsy report says, and the Neuralink implants left parts of her cerebral cortex “focally tattered.”

One doctoral candidate at the California National Primate Research Center told WIRED they question Musk’s claims of the monkeys being close to death, as “these are pretty young.”

“It’s hard to imagine these monkeys, who were not adults, were terminal for some reason,” the candidate said.

The average age of the monkeys was 7.25 years, the Physicians Committee for Responsible Medicine says.

A spokesperson for the University of California, Davis, declined comment to WIRED. It had previously issued a statement, Insider wrote, where it said the research protocols of UC Davis and Neuralink’s collaboration were thoroughly reviewed and approved by the campus’s Institutional Animal Care and Use Committee.

“UC Davis staff provided veterinary care including round-the-clock monitoring of experimental animals. When an incident occurred, it was reported to the IACUC, which mandated training and protocol changes as needed,” the statement said.

When shown what Musk said on X, a former Neuralink employee told WIRED that that was a “ridiculous” claim — if not a “straight fabrication.”

“We had these monkeys for a year or so before any surgery was performed,” the employee, who was granted anonymity for the article, said.

This reporting comes the same week that Neuralink announced it received approval from an independent review board to begin recruiting for the first human trial of the brain implant for paralysis patients.

Musk has been in hot water with the SEC before, when he tweeted that he would be taking Tesla private at $420 a share. The securities fraud charge brought by the SEC was settled after Musk agreed to step down as Tesla’s chairman and pay a $40 million fine. In addition, Neuralink has been under federal probes linked to animal testing in the past as well, WIRED wrote.