Fertility doctor fathers at least 50 children

A quirk of US state laws has allowed a fertility doctor, who fathered at least 50 children by using his own sperm, to escape conviction for the deception.

Dr Donald Cline, 80, ran a fertility clinic in Indianapolis, Indiana, where he helped patients conceive in the late 1970s and '80s using artificial insemination.

Dr Cline told his patients that the donors were medical residents and interns, and that each donor was only used for three successful pregnancies, according to a feature in the April issue of US magazine the Atlantic.

But the couples were unaware the doctor had used his own sperm instead of the donors he claimed had provided the sample.

Over the past few years, dozens of half-siblings now in their 30s have emerged after piecing together their paternity through online forums, Ancestry.com investigations, Facebook, their own sleuthing and DNA testing.