After several rounds of questioning by various security agencies, it was found that 38-year-old Muhammad Ahmad Sheikh Muhammad Rafiq was mentally unstable and his statements were incoherent and without any substance, the officials said.
Mr Rafiq, a Pakistani passport holder, had approached a help desk at the Indira Gandhi International Airport here on April 28 and claimed that he was an ISI agent and did not wish to continue any further and wanted to stay in India.
He had flown in from Dubai and was scheduled to take a connecting flight to Kathmandu the same day, they said.
It was decided that he should be deported. He was sent by Air India's early morning flight on Sunday to Kathmandu, the officials said.
Get the latest election news, live updates and election schedule for Lok Sabha Elections 2019 on ndtv.com/elections. Like us on Facebook or follow us on Twitter and Instagram for updates from each of the 543 parliamentary seats for the 2019 Indian general elections.