A bench headed by NGT Chairperson Justice Swatanter Kumar issued notice to Ravi Shankar while seeking his reply before May 9, the next date of hearing.
A statement issued by the AOL later in the day insisted that the tribunal had not issued the contempt notice but had verbally reprimanded Mr Misra. "Today, no contempt notice whatsoever has been issued by the NGT to the Art of Living... The matter has simply been adjourned until 9 May," the statement said. "We respect the judiciary and have faith that truth shall prevail," it said.
The plea filed by activist Manoj Misra has sought action against Ravi Shankar and said his remarks interfered with with free and fair dispensation of justice.
In a statement published on the AOL's website earlier, Ravi Shankar had blamed the government and the NGT for permitting AOL to hold the function and said his foundation had obtained all necessary permissions, including from the green panel, and the event could have been stopped in the beginning itself if the river was so "fragile and pure".
In the plea filed through advocates Ritwick Dutta and Rahul Choudhary, Mr Misra said the AOL head was "in the habit" of making statements to "denigrate the dignity and status of this tribunal, which was an interference in the fair dispensation of justice", that is the bedrock of the rule of law.