A fertility doctor in Canada was formally reprimanded this week for inseminating at least 11 women with his own sperm and giving the wrong sperm to dozens more women beginning in the 1970s.

Dr. Norman Barwin, 80, was declared "incompetent" by the College of Physicians and Surgeons of Ontario, which Barwin had resigned from in 2014 after patients began to complain that their children were conceived with sperm that didn't belong to the intended father.

The College of Physicians and Surgeons of Ontario found Barwin "committed an act of professional misconduct in that he failed to maintain the standard of practice of the profession" and "engaged in acts or omissions" that "would reasonably be regarded by members as disgraceful, dishonorable or unprofessional," the college said Thursday. "The Discipline Committee also found that Dr. Barwin is incompetent."

Allegations against Barwin date back to 1970, during his time at Ottawa General Hospital and an Ottawa clinic, where he practiced infertility and hormone therapy, weight loss and transgender care, according to the college.

In 2015, the daughter of a patient who had used donor sperm became curious about her genealogy and began research that led her to discover that a second cousin of hers was a relative of Barwin's.

Barwin confirmed through a DNA test that he was her father, but said "the only occasion he had used his own semen was when he was calibrating an automatic sperm counter," and some of it must have gotten mixed up with donor sperm, according to the college of physicians.

Another patient who gave birth to a daughter in 1990 and thought she was impregnated with her husband's sperm later became suspicious when her daughter was diagnosed with celiac disease, a genetic condition that neither she nor her husband have.

The two young women compared their DNA results and did further research to find out that they were half siblings, and Barwin was their father.

They have now identified nine other children who were conceived using Barwin's sperm when he said he was using donor sperm or sperm from his patients' partners.

NBC News was not immediately able to reach a lawyer or other representative for Barwin.

The doctor is accused in a 2016 lawsuit of giving the wrong sperm to an additional 50 to 100 women who later gave birth.

One family describes being traumatized when they found out their two children were not full siblings as they thought but rather half-siblings with different fathers.

Another mother was given incorrect information about her sperm donor and can't get any information about the medical history of her son, who has learning disabilities, because she has no idea where the sperm came from.

Another woman found out that her children were related to one another but not to her husband, whose sperm she thought was used.

"Whether Dr. Barwin’s actions were accidental or willful, the suffering he has caused remains deep and wide," said Dr. Edward G. Hughes, an obstetrician/gynecologist, according to the College of Physicians and Surgeons of Ontario.

He said the full scope of the damage isn't known because many women who undergo fertility services fail to conceive. "For 51 children to have been born with incorrect sperm heritage, as many as 100 may have received the wrong sperm during their treatment," he said.

Hughes also said that failing to clean the chamber after calibrating it with his own sperm likely would not have resulted in a pregnancy from his sperm.

"For a single pregnancy to have occurred in these ways would have been remarkable," he said. "For eleven pregnancies to have been sired in this way over two or more decades is neither statistically plausible nor believable.

"Offspring are living an avoidable genetic disconnection from their fathers and have no access to their genetic heritage," Hughes continued. "The children whom Dr. Barwin fathered himself are burdened in these and other even more profound ways. They know that their own DNA and that of their children and beyond, will always be linked to him and his actions."

Barwin hasn't practiced since 2014. His registration with the College of Physicians and Surgeons of Ontario was revoked earlier this year, and he was ordered to pay a fine of $10,370.