A blunder in a New York IVF clinic led to the birth of twins - one black, and one white - and a heartbreaking legal battle between the parents.

The case mirrors the mix-up revealed on Monday in the UK - and resulted in one twin being given to each couple.

Donna Fasano not only received an embryo created with her egg and her husband Richard's sperm, but another which had been stored earlier at the clinic in Manhattan by another couple.

The parents only realised the mistake when twins of different colours were born in 1999.

The other couple, Robert Rogers and Deborah Perry-Rogers, immediately started legal proceedings to obtain custody of "their" twin.

Legal split

Lawyers acting for them described the boy as a "stowaway".

Bernard Clare told the BBC that, in winning the case, a number of important legal principles had been set.

The courts realise they are a step or two behind the scientific community

Bernard Clare, Lawyer

The Fasanos had argued that the twins should remain in contact, but this was rejected.

He said: "The courts agreed that no-one should force the contact between the children.

"The ruling says that genetics, although not a determining factor in these situations, does play an important role.

"If a mother finds out early on that she is carrying a stowaway, that mother is obliged to try to undo the mistake by avoiding the bond that may be created."

He said that while the differences between the twins in this case had made it easier to come to a fair solution, the UK case - where both babies may be either genetically alien to the couple, or be the product of a stranger's sperm and her eggs, would be far more difficult to resolve.

He said: "The tragedy is compounded in this case."

Case by case

While the US case had set some precedents, he said, it demonstrated that judges would look at circumstances on a case by case basis in future.

He said: "The only real principle that has come out of the case is that there is no hard and fast rule.

"This is because the courts realise they are a step or two behind the scientific community."

Of course, US legal precedent has no bearing on the UK courts, which will begin to unravel the situation in October.

Here, precedent suggests that the woman carrying the children is considered in law the mother - although this could be challenged.

Mrs Fasano, bringing up one of her twin boys in New York, sent a message of sympathy to the mother involved.

Her lawyer Edward Tantleff said: "Her thoughts and prayers go out to the birth mother.

"It was a tough time for Donna and she feels very bad for her."