Wendy Duncan and her husband Brian are white. Nineteen months ago, the Lincolnshire housewife gave birth to a beautiful, healthy, Indian daughter.

Freya, brown-skinned and dark-eyed, is not a medical miracle after a long and fruitless quest through invitro fertilization and adoption, but the product of a booming industry in India that is offering embryos for adoption.

India is fast cornering what is forecast as a £3 billion-a-year market in “reproductive tourism”. It has highly trained, English-speaking doctors and medical procedures that cost a third of the price charged in Europe.

Couples such as the Duncans are lining up to be treated. Their experience was so successful that they are returning next week to the Bombay fertility clinic that produced Freya, to try for a second child.

Mrs Duncan, 41, plans to undergo the same procedure, which involves the implantation of up to five fertilized embryos into her womb. If successful, she will return to England after a short holiday knowing she is pregnant and give birth to another Indian baby.

Embryo adoption was the culmination of an 18-year journey for the Duncans during which their attempts to become parents were frustrated by nature and bureaucracy. Being white and already having a mixed-race child (from Mrs Duncan’s previous relationship) meant that they failed the criteria for a normal adoption.

Invitro fertilization was unsuccessful and expensive for a family relying on Mr Duncan’s income as a lorry driver. The older Mrs. Duncan got, the less the chance there was of any fertility treatment working.

Their options were running out until they stumbled upon a website for the Bombay clinic. It was an easy choice.

“Last time, I knew I was pregnant within three days. It was quick - just like having a smear,” she said. “Couples wait years in the U.K. for egg donation . . . So when we heard about this, we thought ‘Why not?’ If the standards were the same [as British ones], then we didn’t have a problem. And they were. In fact, we were able to get a lot more information. We weren’t just a number.”

The Duncans had no qualms about bearing a child of a different race. They are Freya’s natural birth parents and legal guardians in British law.

“To us color is not an issue. I already have a mixed-race daughter, whose father is Arab, from a previous relationship,” Mrs Duncan said. “Lots of people say you would never think Freya wasn’t ours. She is so like me, it is unbelievable. She should have been a redhead - she has the temperament.”

The Duncans spent £8,000 on one course of fertilization in Britain. Their treatment in Bombay cost £3,000.

Drs. Anjali and Aniruddha Malpani, a husband and wife team, say that two-thirds of the patients attending their clinic in Bombay are from abroad. The Duncans were the first white couple to whom they gave an Indian embryo. It was a situation that raised emotional and ethical questions.

“We invested a lot of time in counselling for this one,” Dr Anjali Malpani said. “It is absolutely ethical if the patient wants it. It is a personal choice. It is a lot like adoption but you have the feeling of a natural pregnancy.”

The booming industry has attracted criticism on ethical grounds. Social workers in India fear that poor women are being exploited for “rent-a-womb” services such as surrogacy, banned for commercial gain in countries such as Australia and China.

British health professionals, meanwhile, fear a rise in multiple births and an added strain on the Health Service. In Britain, embryo implants are limited to two at a time but in India, where there is no law governing fertility aid, doctors can insert up to five.

The council does issue non-binding guidelines but there are calls for the rules to be tightened, rather than relying on clinical discretion.

“The government is thinking along these lines. They have already accredited fertility centers, which are subject to minimum requirements and precautions,” said Dr. Chander Puri, director of the National Institute for Research in Reproductive Health, which created India’s first test tube baby in 1986. “India is at the cutting edge of technology and the success rate in our centers is high compared with the best abroad.” The glowing international testimonials on the Malpanis’ website suggest that they will never be short of people willing to defy medical opinion back home. The images of gurgling babies are their best advertisements.

“People will always look and stare because we are different but I haven’t had one single person say I shouldn’t have done this,” Mrs Duncan said.