Hong Kong (CNN) -- A Bollywood star is facing a storm of controversy over the sex of his unborn child.
India's Health Ministry has launched an investigation into media reports that the actor Shah Rukh Khan and his wife are expecting a boy through a surrogate mother.
Sex determination tests are banned in India, and elsewhere in Asia, due to a traditional preference for sons.
Dr Jignesh Thakkar of the Indian Radiological & Imaging Association told CNN that India's Health Ministry had investigated the case at the association's request.
"We wanted to know how this had been leaked out because it's confidential information that only a doctor and not even a patient knows," said Thakkar, who is the association's coordinator for the Pre-Conception Pre-Natal Diagnostic Techniques Act that bans sex selection.
"Action should be taken against the doctors and the patients who are not following this law. The celebrities or the rich and famous cannot get away with it."
Khan -- who has a 16-year-old son and 13-year-old daughter -- has not yet commented on the issue.
Thakkar said that doctors proven to have divulged an unborn child's sex could face three years in jail and the suspension of their medical license for five years, while parents could face up to five years in jail.
India banned sex detection in 1996 as it attempted to prevent the abortions of girls but, according to Rob Brooks at the University of New South Wales in Australia, this measure has had little impact on the country's skewed sex ratio.
Sex detection tests are also illegal in China, another country where sex ratios are strongly biased toward males, but the ban has done little to correct the country's gender ratio, which in 2011 stood at 117 men for every 100 women. The global average is between 103 to 107 men per 100 women.
"It's not particularly effective because there are always unscrupulous doctors," he said.
"And ultrasound is a really important diagnostic technology so people go and get the ultrasound for other reasons and sometimes you can't help but notice the sex of the child."
Pakistan, Bangladesh, Iran, Afghanistan, Taiwan and South Korea also have unbalanced gender ratios, Brooks added.
Brooks said that, in India, the preference for sons was historically confined to upper castes but as its economy has grown and the technology for sex selection made more widely available, the middle class had adopted the practice.
In China, the preference is magnified by the country's one-child policy and campaigns to stress gender equality are undermined by provisions that allow families in rural areas to have a second child if the first is a girl.
"Rich people want to have a male heir to inherit the family fortune, while people in rural areas want strong manpower and farmers think boys can do more to the help the family," Zhang Zhongtang, an expert in family planning from the Chinese Academy of Social Sciences told the Global Times in March.
Brooks said that banning abortion for sex selection is just one small part of the measures needed to change attitudes, with improvements needed in women's rights to property ownership and better pension provision to reduce parents' reliance on their children along with reform to dowries and dowry like systems.
But change is possible. Through legal reforms and a "love your daughter" public awareness campaign that highlighted the dangers of skewed sex ratios, South Korea managed to reduce its sex ratio at birth from 116 men per 100 women to 107 by 2007.