The moment he received the approval, Montgomerie began to look for his first collaborator, whom he found in Mahomed-i-Hameed, better known by his code name, the ‘Moonshee’. (source)
Mahomed-i-Hameed appears to be the name of a person, not a place, and the antecedent noun of the pronoun "whom". Then why is in used before the name of a person? What does it mean to "look for a person in a person"? I thought you could only look for a quality/attribute in a person.