More people in the Netherlands are now checking whether they may be offspring of a deceased Dutch fertility doctor confirmed by DNA to be the biological father of 49 children so far, the Associated Press(AP) reports. DNA test results, revealed earlier this month, show that Jan Karbaat, MD, who died in 2017 at age 89, was the biological father of the 49, having swapped his own sperm with chosen donors' sperm without the parents' knowledge. Most of the children are adults now, many with children of their own. Dutch fertility doctor Jan Karbaat The AP reports that Ties van der Meer, from the Dutch Donor Child Foundation, said last week that three more people contacted him suspecting they may also be Karbaat's offspring. The revelation of the DNA results followed a 2-year court battle waged by dozens of people who suspected they may be Karbaat's children. They sued to force the family to release the doctor's DNA profile, which was locked in a safe, according to the Guardian . The family fought the disclosure, stating privacy reasons. Clinic Closed in 2009 The AP reports that Karbaat's fertility clinic in a suburb of Rotterdam was ordered closed in 2009 because of poor administration and record keeping. The Guardian reports that before his death "Karbaat reportedly admitted to having fathered about 60 children in his time at the discredited clinic." Iara de Witte, a children's rights adviser at the Dutch office for Defence for Children, told Medscape Medical News that "The interests of the child, the right to know who your parents are, is acknowledged and prevailed over the right to privacy of the doctor and his family." She said the doctor claimed that children conceived before 2004 with donor semen do not have the right to know who their genetic father is, as donorship happened anonymously, as a rule. She said, however, that this case was not about anonymity of the donor but about whether the doctor used his own sperm. "The court took very seriously that the doctor violated his professional duty of care," she said. "We as Defence for Children hope this is only the first step in breaking the anonymity of donors from before 2004," de Witte said. "We know from other cases that there are more clinics as well that may have violated their professional duty of care. We hope that also in some of these cases, the right of the child to know your parents outweighs the right to privacy of the donor." Other court cases of fertility doctors secretly donating their own sperm have been widely reported. Last year, Medscape Medical News reported that Donald Cline, MD, an Indiana fertility doctor who admitted to using his own sperm to impregnate women, surrendered his license. He ran a fertility clinic in the 1970s and 1980s in the Indianapolis area and allegedly may have fathered dozens of children, unbeknownst to the couples who came to him seeking an anonymous sperm donation. Also last year, Medscape Medical News reported on a lawsuit filed by a woman in Benton County, Washington, born in 1981, who learned through Ancestry.com that she had a father-daughter match with the fertility doctor for her parents. Source