Ministers are to consider creating a separate birth register for children conceived by anonymous sperm donation, allowing details of their true origins to become officially available for the first time.
The plan would force thousands of parents to tell their children about their genetic heritage, as it would be written on their birth certificates and would remove the secrecy that surrounds conception through assisted reproduction.
The proposal is one of five options drawn up by the Department of Health to deal with the issue of donor insemination, which will be presented to ministers in the next two weeks. A public consultation document will be produced shortly.
In Britain, more than 10,000 children have been born using donor insemination (DI) since 1991. Last year 1,349 babies were born using the technique.
Nearly all of these children have no idea of their origins, because more than 90 per cent of parents who conceive a child using sperm from an unknown male donor do not tell them that their "social father" is not the genetic father.
Research has shown that most parents are worried that telling the truth will undermine the child's relationship with the social father. But many psychologists believe the damage caused by family secrets can be far more devastating.
Children conceived by donor sperm have a birth certificate that identifies their social father but does not give any indication of the intervention of medical technology or any clues as to their real origins.
Giving children the right to trace their genetic fathers, in a similar way that adopted children were given the right to find their biological parents in the 1970s, is the most controversial option under consideration.
Changes in the law could also mean that men would only be able to give sperm if they were willing to be identified to any future children.
Health experts have criticised any removal of the anonymity of sperm donors, saying that it will destroy the fertility industry and lead to an acute shortage of sperm for infertile couples.
A spokesman for the Department of Health confirmed: "The options being considered range from the status quo to complete disclosure of all information."
Since 1991, all clinics doing fertility work must be registered with the Human Fertilisation and Embryology Authority, and all sperm donors give basic information - name, national insurance number, known medical history and hobbies and interests.
The DI offspring have no right to access this information, although they are told, if they are intending to marry, whether or not their future spouse is a half brother or sister.
Supporters of a separate register for donor insemination children say that this lack of honesty about someone's origins leads to long-term social and emotional problems. Those who are never told often suffer from identity crises. Those who are told may feel frustrated, because they are blocked from finding out further information about their genetic roots.
Six DI adults have spoken to The Independent. They said depriving them of the right to know was an abuse of human rights. Many were not told until adulthood. A spokesman for the Donor Conception network, which encourages parents to tell their children about their origins, said that a separate register for DI children was the "right moral stance".
But Tim Hegley, a spokesman for Issue, a charity that supports infertile couples, asked: "Why should infertile couples be forced to reveal things that fertile couples are not?"