The man, identified as Kamaal Fariyadi, was roaming around Kashmir House and the Army Chief's residence this evening and was detained by security men posted there who found his movement suspicious, a senior police officer said.
He was later handed over to Delhi Police for further interrogation, he said.
Currently, he is being jointly interrogated by Delhi Police's Special Cell, IB and district police to ascertain the reason for his visit there, he said, adding that he has not spoken much during questioning.
During questioning, the Afghan national took the name of a doctor who he was consulting for treatment, a senior police officer said, adding they are trying to ascertain the verity of his claim.
The man was also not carrying any ID proof and when asked, he could only furnish the photocopy of an ID, the officer said.
He has been evasive during questioning and police will try to find further information about him on their own, the police officer said.