One of the most devastating realizations as a father is to become aware that a child that you have loved and raised is not biologically yours. It is more common than people may think that a mother was in full knowledge of the true paternity of a child since conception, but had purposefully deceived people in order to gain child support or another form of support from the person she stated was the father.
A man in this position will feel a wide range of emotions, but one of the concerns or questions that he will have is whether he is able to be reimbursed by the mother on the child support that he wrongfully paid. He might also be wondering whether there is any type of legal action he can take against the mother for engaging in purposeful deception in order to make a personal gain.
When a father finds out that a child is not related to him biologically, he has a right to go to the courts and request that the child support orders can cease. However, the court will always consider the situation in full and ask themselves what ruling will be in the best interests of the child. They are likely to conclude that no further payments are necessary; however, if they believe that the child will suffer from this, they may rule that the father needs to continue payments regardless.
Reimbursement for past child support payments is considered quite unlikely. However, many victims of paternity fraud have made attempts to do this by taking their cases to the civil court.
Source: The spruce, "Help for victims of paternity fraud," accessed Oct. 12, 2017