The Special Task Force (STF) today arrested Irfan Khan, a Unani doctor, in connection with the terrorist attack at the disputed temple complex in Ayodhya. Khan, who belongs to Saharanpur, used to run a clinic in Delhi’s Sangam Vihar.The STF also located a hideout in Akbarpur from where the terrorists are suspected to have travelled to Faizabad and then, Ayodhya.STF inspector-general Arun Kumar Gupta told The Indian Express that Khan, who was arrested from Nakud, had been in constant touch with the terrorists — they had made at least seven calls to him from Akbarpur. Khan has been booked under the Unlawful Activities Act. Efforts are on to take him on remand for further investigations, Gupta said.The apartment on Deoli Road in Delhi that the terrorists occupied was opposite Khan’s clinic. The doctor soon grew friendly with the quartet and even took one of them, Zuber, to his cousin’s wedding at his native place, Nakud, in Saharanpur, on March 20. ‘‘Khan gave a ride to Zuber on his motorcycle and took him to Deoband as well,’’ said Gupta. On one occasion, the two also stayed together at the house of Abdul Rehman in Muzaffarnagar.The STF is yet to establish whether Dr Khan was part of the sleeper cell or just a symphatiser. ‘‘We are looking into his accounts to establish the extent of his involvement. But we are certain he was aware of the attack,’’ Gupta said.Investigations in Akbarpur led police to a house in Shahjahanpur in Shajadpur which the terrorists had rented. Gupta said one of the terrorists identified himself as Ram Singh and his accomplice as a nephew and rented the house of Arvind Sonar for Rs 600 in April. He told Sonar that he was from Lucknow and ran a gutkha business. The two left the house in May and re-occupied it in June.In the house, police found a charred piece of a driving licence issued in the name of Arshad Ali. The licence, issued in Amritsar, was used by militants to purchase a SIM card from Sultanpur. The STF also found a torn hand-drawn map of Ayodhya and newspapers of July 4.