Twins' marriage sparks debate over rights of adoptees

Twins separated at birth and adopted into different families married each other without realising that they were related, Lord Alton has revealed. The pair, whose identity has been kept secret, met as adults and married after feeling what the peer described as "an irresistible attraction".

When the couple discovered the truth about their incestuous relationship, they were granted an annulment by the courts, which ruled that their marriage had never actually existed. Their plight sparked widespread debate over the rights of children to know the identity of their birth parents.

Lord Alton, who learnt of the disturbing case from a judge involved in the case, referred to it during a House of Lords discussion on the Human Embryology and Tissues Bill. The Bill, which if passed will relax the rules governing fertility treatment, will be voted on in the Lords on Tuesday.

Lord Alton used the twins' case to support his argument that birth certificates should be changed to include information on both the genetic parents, as well as whether or not the child was conceived by a sperm donor.

He insisted: "The state is colluding in a deception. We are opening the door to more cases like this one. The issue here is about human rights." A German man recently served a two-year prison sentence after fathering four children with his sister, from whom he was separated at birth.

The couple are now campaigning for the right to continue their relationship in violation of the country's ban on incest.