The allegation by co-chair of the expert group Sunita Narain came a day before the high court is likely to start further hearing in the case.
Narain also said that she was in favour of a ban on junk food in schools and a canteen policy that will categorise food into red, orange and green groups. The "red category food, which is junk food, will not be allowed in schools", she said.
She said the Food Safety and Standards Authority of India (FSSAI) had in March 2014 submitted to the high court a set of guidelines for "making available quality and safe food in schools".
Narain said the guidelines were framed by the expert group, which was set up by the FSSAI as per the direction of the court in September 2013.
The court direction came on a public interest litigation (PIL) filed in 2010 by Uday Foundation, a Delhi-based non-profit organisation, seeking a ban on junk food in schools and surrounding areas, regulation of junk food promotion and advertisement, and development of a school canteen policy.
"However, a close look at the guidelines submitted to the court by FSSAI reveals that they are ineffective in addressing the prayers of the PIL. We believe the food industry has worked to influence the guidelines... As a result, a diluted set of guidelines has been submitted to the court," said Narain, who is also the Director General of the Centre for Science and Environment (CSE).
She said that this is not the same set of guidelines that was framed by those who are best suited to do so -- eminent paediatricians, public health specialists and nutritionists.
Narain said last-minute changes in the guidelines include 'restricting/limiting' availability of junk food in schools and surrounding areas, instead of a complete ban that was suggested by the expert panel.
"No criteria is mentioned to ascertain what is meant by restricting/limiting and who would monitor, thereby making implementation ineffective," she said.
Criticising the "diluted" version of the guidelines, she said the regulatory area near a school has been reduced from 500 yards to 50 metres, thereby limiting the purpose of it.
"...no recognition of the term junk food in it. However, the Hyderabad-based National Institute of Nutrition defines junk food as food that contains little or no protein, vitamin or minerals but is rich in salt, fat and energy," she said.