Prosecutors say he may have used his sperm to inseminate patients 50 times.

The woman knew her biological father had been a sperm donor, according to court documents. The doctor had told her mother that he would use an anonymous medical student to help her conceive.

For years that story stood. Then advances in genetics and an ever-expanding online universe toppled not only that story but also the reputation of the fertility doctor behind it.

When the woman went online to find genetic relatives, she discovered at least seven siblings, court documents say. The one thing they had in common? Dr. Donald L. Cline, the Indianapolis physician who helped their mothers conceive.

On Monday, Cline, 77 of Zionsville, appeared in Marion Superior Court for an initial hearing. He is charged with two felony counts of obstruction of justice after telling an investigator that he never inseminated his patients with his own sperm, according to court documents. Paternity tests on two of the siblings revealed a 99.9 percent probability that Cline was the father, records show.

Cline pleaded not guilty to the charges.

The case, first made public through a Fox59 investigation, has revealed how reproductive technology and laws are rapidly changing – and how those changes can have dramatic effects on individual lives.

In a Change.org petition calling on state officials to investigate the doctor, one of the siblings wrote she suspected the doctor used his sperm “countless times.”

“I am outraged by this clear breach of ethics in the field of medicine,” she wrote, adding this practice could lead half-siblings and other related individuals to wind up marrying without realizing their connections to one another.

A number of websites helped the siblings — born in the late 1970s through mid-1980s — piece together the story behind their conception, according to court documents. The siblings used 23andMe.com and Ancestry.com for DNA testing and research, and the Donor Offspring, Parent & Sibling Registry, a website where donors and offspring can search for genetic relatives.

Not only did they discover their relation, they also learned they were linked to 70 of Cline’s relatives.

Then, they wondered, if the doctor or one of his relatives was their father. After a sibling contacted Cline’s family through Facebook, some of the siblings met with Cline in spring 2016.

At that meeting, according to court records, Cline told one of his alleged biological daughters that he felt pressured to use his own sperm when he did not have access to donor sperm. He said he donated sperm about 50 times.

“It was unethical what he did. He was telling his patients one thing and doing another,” one of the siblings told Fox59’s Angela Ganote. “I want to find out as much truth as I can but I know deep down that we never will know the complete truth as to how many siblings we do have.”

Such stories were not uncommon before the advent of commercial sperm banks in the early 1990s.

Wendy Kramer, who runs a website to help connect parents, donors and people conceived through donation, offers one piece of advice to people born before 1990 looking to learn the identity of their mother’s sperm donor: Check out your mother’s fertility doctor.

“It’s a little bit creepy that I have to tell them that,” said Kramer, co-founder and director of Colorado-based Donor Sibling Registry.

Fresh donor sperm was commonly used in artificial insemination until the advent of HIV in the mid-1980s, experts said, often provided by medical students. Then, clinics began using cryopreserved, or frozen, sperm that had been quarantined and tested, a practice that continues today.

New technologies that assist with male reproductive problems also have made the use of donor sperm less common for heterosexual couples, said Dr. Laura Reuter, medical director of Carmel-based Midwest Fertility Specialists. Donor sperm today is most often used for single mothers by choice and lesbian couples.

Reuter called Cline’s alleged behavior “deceptive and immoral,” but said the field has changed dramatically since the early 1980s.

“We have to go back and remember that that was a different era,” she said.

Four of the siblings in the Cline case have filed complaints with the Indiana Attorney General’s Office, according to the probable cause affidavit filed by the Marion County prosecutor’s office.

The attorney general’s office, which first investigated Cline, has not filed any formal action against Cline, who retired in 2009.

During the attorney general’s investigation of the complaint, Cline wrote in a January 2015 letter that he received donor sperm from resident doctors and dentists between 1971 and 1981. He said he had a policy not to use a donor for more than three successful pregnancies.

“I can emphatically say that at no time did I ever use my own sample for insemination,” Cline wrote in the letter.

Cline went on to accuse his accuser of libel and slander.

“I followed suggested guidelines of the period,” Cline wrote, according to court records. “I also did nothing morally or legally wrong.”

He told the attorney general’s office the records of the individuals who made the complaints were destroyed, in keeping with state law which only requires doctors to maintain records for seven years after the last date of treatment.

But the prosecutor’s office charged Cline with obstruction of justice, saying he misled investigators, according to court documents.

A prosecutor’s office spokeswoman said in an email that the obstruction of justice charges filed last week “were the most appropriate based on the evidence available.” The email also said that no additional criminal charges were expected.

Legal experts, however, said that Cline could be liable for breaking a number of laws, from violating principles of informed consent to fraud.

In general, reproductive medicine is not as regulated as other areas of medicine, said David Orentlicher, co-director of the William S. and Christine S. Hall Center for Law and Health at the Robert McKinney School of Law at IUPUI.

“One of the unfortunate realities is the extent to which assisted reproduction is not regulated,” Orentlicher said. “There aren’t as many legal regulations as there should be.”

Civil cases such as this one may wind up settled before they ever go to trial, said Jody Madeira, a professor at the Indiana University Maurer School of Law, who is writing a book about infertility, emotions and doctor-patient relationships.

At the time Cline is alleged to have done this, doctors had no way of foretelling that one day websites like 23andMe could act as genetic tattletales on misdeeds done decades before. Even today there are few laws on the books regarding sperm donation, Madeira said.

“It’s unforeseeable at the time,” she said, “but it seems like people should have some kind of claim because they endured this huge indignitary violation. The entire thing is just profoundly disturbing.”

Jim Monroe and his wife find the allegations disturbing as well. Cline helped them conceive their son through in vitro fertilization in 2005. The allegations have shaken his trust in the doctor and the procedure, Monroe said.

“There’s really no way of knowing that it was actually my (sperm) that fertilized my wife’s egg and was put back in her,” Monroe said.

Monroe said he plans to get a DNA test on his son, “for the peace of mind.”

Cline was a well-known local physician throughout his career. In 1979, he stopped his obstetrics practice and devoted himself to the field of fertility. In 2000, he helped pioneer a technique to freeze the extra eggs of women undergoing in vitro fertilization, rather than discarding those not used to create embryos.

At the hearing Monday, Magistrate Stanley Kroh ordered Cline to be released on his own recognizance. He scheduled another hearing for Oct. 17.

Kramer, of the Donor Sibling Registry, said she was not surprised that additional charges had not been brought against Cline.

“He didn’t break any laws, because there are no laws,” she said. “The reproductive medicine industry in regards to sperm donations…is generally a free-for-all and at the expense of the very children we are creating.”