Several people in this thread have made the proposition that legal parenthood should be *automatically* anulled when it turns out the man who accepted fatherhood on the premise that is the biological father is not in fact the biological father. Have you really thought this through? Does it work both ways?
I mean, I have two kids aged 10 and 2, and I love those and believe I've earned myself a place in their life. If either of them turned out not to be biologically mine, I may be angry at their mother for lying to me but I'd certainly want to continue to play a role in their life. Under your proposal, I'd have no basis to claim even as much as visitation rights, right? Is that what you want?
Or what about other (admittedly more far-fetched) scenarios where the father, or both parents, have been misled about the identity of a child's biological parents, where the wife is not at fault? Say for example, a couple is opting for in-vitro fertilization and five years later, it turns out the hospital messed up their sperm samples so the husband isn't actually the child's biological father. Does he now get to rescind all obligations towards the child? Does the wife get to deny him visitation should they divorce? What if he *knew* it wasn't his child since they made use of a sperm donor due to his infertility, but they were misled about the sperm donor's identity. Do they now get to send the child to an orphanage?
I'm not at all saying that that what the OP reports is fair. What I am saying is that an automatic nullification of parental obligation even after many years when it turns out they were uninformed about the biological parents of the child is a cure worse than the disease.