What are the odds?

Totally strange. British twins separated at birth married without knowing of kinship.

London - A pair of twins in Britain who were separated at birth and adopted by different families married each other without realizing they were brother and sister and have now had their union annulled by a court, it was revealed Friday. The extraordinary case, brought to public attention by David Alton, a liberal member of Britain's House of Lords, prompted calls Friday for legislation enshrining a child's right to know who her or his biological parents are.

The twins, whose marriage was recently annulled by a High Court judge because "it never validly existed," had felt an "inevitable attraction" to each other, Lord Alton said Friday.

Details of the identities of the twins involved have been kept secret, but Lord Alton said the pair did not realize they were related until after their marriage.

"They were never told that they were twins," Alton told the House of Lords. "They met later in life and felt an inevitable attraction, and the judge had to deal with the consequences of the marriage that they entered into and all the issues of their separation."

According to Alton, the case raises the wider issue of the importance of strengthening the rights of children to know the identities of their biological parents.

"If you start trying to conceal someone's identity, sooner or later the truth will out," he said.

"The right for children to know the identity of their parents is a human right," said Alton.

Pam Hodgkins, of the charity Adults Affected by Adoption, said there had been previous cases of separated siblings being attracted to each other.

"We have a resistance, a very strong incest taboo where we are aware that someone is a biological relative," she said. "But when we are unaware of that relationship, we are naturally drawn to people who are quite similar to ourselves."