From Sky Twins separated at birth have married each other without realising they were brother and sister, it has been revealed. The British couple's marriage has now been annulled by the High Court after judges ruled the marriage had never validly existed. The identities of the brother and sister and details of how they fell in love and married are being kept secret. Soon after they were born they were separated and adopted by different families. Neither was told they had a twin and had no idea they were blood relatives until after their wedding. Professor Lord Alton uncovered the case when a High Court judge told him of a hearing he had dealt with. "They were never told that they were twins," said Lord Alton. "They met later in life and felt an inevitable attraction." Experts say their case reinforces the need for children to have greater rights to know the identity of their parents. Lord Alton believes the implications for in vitro fertilisation are huge - children conceived in this way can have as many as 10 IVF brothers and sisters. He warns that new reforms drawn up by ministers could undermine existing rights. The changes, now being debated in the House of Lords, would relax rules on who can have fertility treatment and clinics would be unable to bar single women and same sex couples from treatment. Critics say it will weaken further the link between children and their biological parents - and even effectively end the need for fathers. "The right for children to know the identity of their biological parents is a human right," he insisted. "There will be more cases like this if children are not given access to the truth. The needs of the child must always be paramount."