Police sources said Singh, a retired army Havaldar's son, had lodged the militants in a government accommodation near his work place in Tangmarg area in North Kashmir.
The militants had met in Tangmarg on March 11, before coming to Srinagar on March 12.
This comes after the arrest of suspected Lashkar militant Talha Zarar and trans-border courier-cum-double agent Bashir Ahmed Mir alias Haroon.
According to sources, it was a SIM card recovered from the dead militants which led to Talha's arrest, who later revealed the names of Mir and Singh during his interrogation.
Mir had also arranged for a hideout in Srinagar and travelled to Bemina where the two militants were dropped for the attack.
According to Singh's wife, the militants stayed with Singh in Tangmarg. Independent sources told HT that Singh had been arrested once before in 2001for possession of fake currency.