Dr Anil Sabhani and his X-ray technician Kartar Singh were each given two years in jail and fined 5,000 rupees (£62) by a court in the northern state of Haryana.

Both the use of technology to determine the sex of an unborn child and the termination of pregnancies on the basis of gender are illegal.

Despite the law being widely flouted since it was introduced 12 years ago, no doctor had until now had been sentenced to jail; previous convictions led only to a fine.

Dr Sabhani was caught in a sting operation when government officials sent three pregnant women to his clinic in Faridabad, on the outskirts of Delhi, in 2001.

He was captured on video and audio recorders telling one woman that she was carrying a girl and that it could “be taken care of”. His clinic was immediately raided by the team and documents recording the procedure were seized.

“The entire episode involving the decoy patient had been videoed, making the conviction possible,” said Dr R. C. Agarwal, the head of Haryana’s Appropriate Authority, the body responsible for enforcing the law.

While passing the prison sentence, the judge said that the declining number of girls was horrific. “It is due to the illegal acts of persons like the convicts that the sex ratio is declining day by day,” he said.

Although the practice of sex determination has been outlawed since 1994, the number of female foetuses being aborted is rising as urban Indians gain access to ultrasound equipment.

The exact number of terminations as a result of sex selection is unknown, but the Indian Medical Association estimates that five million girls are aborted each year.

However, according to more conservative figures published in The Lancet this year, more than ten million female foetuses may have been aborted in India in the past 20 years after gender checks.

“Sex selection is a high-volume, low-risk business,” said Dr Puneet Bedi, a specialist in foetal medicine based in Delhi. “Volumes have to be high because one or two cases don’t get the errant doctor much money. It’s low risk because hardly anyone is ever caught.”

The practice is a particular problem in northern India, where the status of women is low. It has led to a skewed sex ratio in wealthier states such as Punjab, where the latest census shows that there are only 793 girls to 1,000 boys. Nationally, there are 927 women to every 1,000 men.

Experts are concerned by recent research that found the more educated a woman is in Delhi, Chandigarh and Punjab, the more likely she is to use modern technology to determine and abort girls.

Driving the problem is the traditional preference for sons. Daughters are often viewed as an economic burden on their parents because of the vast dowries they are commonly expected to pay.

While a boy is viewed as a breadwinner who will boost a family’s income, a girl is often seen as a liability because she will eventually belong to her husband’s family and financially benefit them.

Campaigners welcomed Dr Sabhani’s prison sentence. “This is what can happen when someone decides to implement the law,” said activist Sabu George.

“But Faridabad is just one district in the country and the situation won’t improve until there is similar action in every district.”

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