Greenpeace activist Priya Pillai shows her passport on which airport officials stamped 'offload'.
The government has been asked by the Delhi High Court to explain why it had barred a Greenpeace staff member who held a valid visa from flying out of the capital.
Priya Pillai, a senior campaigner, was on her way to London earlier this month when immigration officials stopped her and stamped "offload" on her passport.
Ms Pillai took legal action on breach of personal liberty grounds against the move, which the environmental campaign group described as "bullying" by the government.
Ms Pillai's lawyer Indira Jaising said the court asked three government departments to explain the January 11 "offloading" by next month.
"The Delhi High Court today issued notices to the home ministry, intelligence bureau and immigration department asking them to reply before February 6," she told news agency AFP.
Officials told Ms Pillai at the time that she was barred from leaving the country and they were "just following orders from the Indian government".
Prime Minister Narendra Modi's government tightened controls over foreign fund transfers to Greenpeace India in June, following accusations in an intelligence report that foreign-funded campaign groups were hurting India's economy.
But the Delhi High Court last week reaffirmed an earlier court order to unblock the thousands of dollars of Greenpeace funds.
Activists allege that the government is being vindictive against groups whose campaigns for the environment are delaying industrial projects.