A top Indian doctors' association has disputed a report which says more than 10m female births may have been lost over the past two decades.
India banned gender selection and selective abortion in 1994
Researchers in India and Canada said in the Lancet journal prenatal selection and selective abortion was causing the loss of 500,000 girl births a year.
But the Indian Medical Association said pre-birth gender checks had waned since a Supreme Court crackdown in 2001.
There has been no reaction from the Indian government.
A spokesman for the Indian Medical Association acknowledged that prenatal selections used to take place, but said they were not as widespread as before and that the Lancet report was exaggerated.
"This has not been happening for the past four or five years after strict laws were put in place," the spokesman, Dr Narendra Saini, said.
The research by Prabhat Jha of St Michael's Hospital at the University of Toronto, Canada, and Rajesh Kumar of the Postgraduate Institute of Medical Research in Chandigarh, India found that there was an increasing tendency to select boys when previous children had been girls.
Indian experts differed over the findings.
"It is a sensational piece of work," Sabu George, who campaigns against female foeticide, told the AFP news agency.
"We are very, very concerned about this study."
Others say it is impossible that India could have lost 10m females.
"If there were half a million foeticides a year, the sex ratio would have been very skewed indeed," said Prof SC Gulati of Delhi's Institute of Economic Growth.
In 1994, India banned the use of technology to determine the sex of unborn children and the termination of pregnancies on the basis of gender.
However, research for the year 2001 showed that for every 1,000 male babies born in India, there were just 933 girls.
Leading campaigners say many of India's fertility clinics continue to offer a seemingly legitimate facade for a multi-billion pound racket and that gender determination is still big business in India.
The researchers said the "girl deficit" was more common among educated women but did not vary according to religion.
Experts in India say female foeticide is mostly linked to socio-economic factors.
It is an idea that many say carries over from the time India was a predominantly agrarian society where boys were considered an extra pair of hands on the farm.
The girl child has traditionally been considered inferior and a liability - a bride's dowry can cripple a poor family financially.