The Australian Law Reform Commission's stance is that it is not in the best interest of a child to have his or her DNA tested for paternity without the mothers consent. Thus reinforcing the role of the mother as a gatekeeper.
There are two scenarios where it is possible that a mother will unknowingly be raising a non-biological child.
It has been documented that babies have been switched accidentally whilst they are in hospital and 2 mothers will unknowingly raise a non-biological child thinking it is theirs. Sometimes this mistake is discovered many years later.
The second scenario is where a couple using the IVF programs for infertility. The woman can be accidentally implanted with embryos from another woman. Unless the embryo is of another race, it is highly unlikely this mistake will ever be discovered.
In the above scenario's when the mistakes have been discovered there is an obvious legal recourse that the mothers can take.
Some fathers will be willing to raise another man's child. These fathers either adopt the children or in the case of infertility, raise children born in their relationship through donor insemination. In both these cases the father makes an informed choice and decision to accept non-biological children as his own.
In Australia 75% of DNA testing for paternity confirmed paternity. So for the vast majority of fathers their paternity has been confirmed. But for the other 25% the news was not good. These men discovered that children they had been led to believe were their biological offspring are in fact related biologically to another man.
The statement "in the child's best interest" is synonymous with what is in the best interest of the mother. For the vast majority of mothers who have deceived boyfriends and husbands it is not in their best interest to have this deception exposed. Many of them would have knowingly kept the child's alleged father in the dark. Not having the courage or the fortitude to be honest and to take responsibility for their actions.
The argument for preventing fathers from having DNA testing on their alleged children is that it could spoil the happy family harmony. Paradoxically during the recent inquiry into child custody and the presumption of 50-50 the opposing argument was put forward that it was not in the child's best interest to have greater contact with their fathers.
DNA testing and shared parenting are not in the best interests of the mother. The denial of the right for fathers to choose to have their alleged children tested for paternity and the denial of shared parenting reduces fathers to little more than sperm donors and paypackets.