I have heard that there is a law somewhere in American or European legal systems that says children have a right to know who their biological parents are.
Where can I find such a law and its details?
An adopted child can apply for their birth records once they are 18 years' old.
There are different processes for doing this depending on the particular circumstances, and if they were adopted before 12 November 1975 they will need to attend a counselling session with an approved adoption advisor first.
On April 1st, 2005, the law changed with regard to egg, embryo and sperm donations in the UK, removing the guarantee of anonymity for the donor and allowing any persons conceived using their donation to have access to the donors identity and contact information.
This law change was also made partially retroactive, so any donations made before April 2005 and after August 1st 1991 (when records were mandated to be kept for health reasons) are also covered by this removal of anonymity for certain information about the donor.
If you donated after April 1st 2005, upon reaching the age of 18 a person can request the following information about you:
This is not uniformly the law in all U.S. jurisdictions and probably not even in most U.S. jurisdictions.
It is also not a right arising under the U.S. Constitution. Generally, the right, if it exists, arises under state law, although there are special rules under a federal statute for children whose relinquishing parents or parents whose parental rights are terminated, are affiliated with a federally recognized Indian tribe.
There is a right to know who your legal parents are, which is available on your own birth certificate.
There is not a right to know, for example, that the man who was married to your mother at the time that you were born, who is listed on your birth certificate, is not your biological parent, or that you were conceived with donor sperm or donor eggs or both.
A child's rights to determine who gave them up for adoption in cases of adoptions vary by jurisdiction and by type of adoption and by date of adoption. Generally speaking, the modern trend is to make it easier for an adopted child to learn the identity of someone who gave them up for adoption, but this isn't universally true. Often an adopted adult can formally express a desire to know who the persons who relinquished them were, which will only be disclosed if the relinquishing persons affirmatively agree to the disclosure.
Adults do have a legal entitlement in the U.S. to obtain genetic testing for themselves (at their own expense), and this can be used in some circumstances to determine who one's biological parents are, but usually this requires some voluntary disclosure from the putative parent or from a relative of the putative parent (from whom a genetic relationship can often be inferred).