My brother discovered that the daughter he has been supporting after divorce is not his by blood, what should he do?

He is not the type to show emotion. But when he got the DNA results, he sat in silence for hours. The girl he believed to be his daughter, the child he had held, supported, and loved for years, was not his by blood.

He and his ex-wife divorced five years ago. They have two children together. When they parted ways, they agreed each would raise one child. He took their son; she took their daughter. Despite the separation, he never stopped being a father to both. He visited his daughter often, called to check in, and sent money every month without fail. No court order compelled him. He simply did what he thought a father should do.

But over time, small doubts crept in: subtle differences he could not quite explain. Eventually, those doubts led him to quietly request a DNA test. He did not tell anyone, not even me. When the results arrived, they shattered him. The girl he had tucked into bed, comforted when she cried, cheered on at school events, was not his biological child.

He has not told her. He has not confronted his ex-wife. He does not know what to say, or even what he wants. Anger mixes with confusion. Sadness bleeds into betrayal. He is questioning everything, not just the money he gave, but the moments, the memories, the years.

He wonders: Was it all a lie? Should I feel like a fool? Should I still care for her like I used to? And somewhere, beneath all that hurt, is a deeper question: Is biology the only thing that makes someone a parent?

This is not just a legal dilemma. It is an emotional reckoning. Can love built on a lie still be real? Does truth erase the bond of time and care?

My brother is lost, and I don't have the answers. We are reaching out to lawyers now, yes, but also searching for something more: clarity, peace, and maybe a way to heal. Because the truth, painful as it is, does not erase the love he gave. And it does not tell him what to do next.

Hoang Anh Son, a lawyer with the Ho Chi Minh City Bar Association, offers legal insight into paternity disputes under Vietnamese law:

Determining legal parentage

According to Vietnamese law, a child is legally considered the common child of a husband and wife if:

The child is born or conceived during the marriage;

The child is born within 300 days of the marriage's termination;

The child is born before the marriage was officially registered but has been recognized by both parents.

Challenging or establishing parentage

If a parent does not recognize a child, they must provide evidence to support their claim, and the matter must be resolved in court. Likewise, when someone seeks to have a parent-child relationship legally recognized, they must submit evidence—potentially including a DNA test. The person requesting the test is responsible for paying the associated fees.

In cases where a man suspects he is not the biological father of a child, he must file a petition with the relevant court to request official acknowledgment that no biological relationship exists.

Child support obligations

Vietnamese law requires the non-custodial parent to provide child support following a divorce to ensure the child's well-being. While courts may not always enforce this immediately, a father who believes the child is his should continue paying child support until the matter is legally resolved.

If a man has credible evidence that he is not the biological father, he may seek to terminate his child support obligations by filing a legal request to disprove paternity.

Seeking reimbursement or compensation

Current Vietnamese law does not specifically provide for the reimbursement of previously paid child support. Future payments are also generally voluntary if legal paternity is not established. However, the individual may file a civil lawsuit against his ex-wife to seek compensation for any damages, if applicable, in accordance with the law.