The operation was carried out jointly by the Uttar Pradesh ATS and Maharashtra ATS. Khan is currently being interrogated in Mumbai.
Wanted since 2008 with a Lookout Notice issued for him, Khan was arrested when he arrived from an undisclosed location to Mumbai.
Khan is a resident of Fatehpur's Hathgaon village, that falls under Bandipur police jurisdiction in Uttar Pradesh.
Investigators said that based on the lookout notice, Khan was detained at Mumbai Airport. The UP ATS was informed, which sent a team to Mumbai for further investigations.
Two terrorists arrested for the 2008 attack on a CRPF camp in Rampur had told police that Khan had acquired terror training in a terrorist camp in Muzaffarabad, Pakistan.
He was also a handler for a Pakistan ISI agent Aftab, who was arrested in Faizabad. Khan sent finances to Aftab, according to investigations.