Claiming responsibility for the shooting on the Reina venue, the group described the gunman as an "heroic soldier of the caliphate who attacked the most famous nightclub where Christians were celebrating their pagan feast".
Police have arrested twelve people as they hunt for the perpetrator, while Turkey's deputy prime minister Numan Kurtulmus said authorities were close to identifying him, thanks a obtaining fingerprints and a description.
IS said the man fired an automatic rifle and detonated hand grenades in "revenge for God's religion and in response to the orders" of IS leader Abu Bakr al-Baghdadi.
Meanwhile, officers raided an apartment in the Zeytinburnu district of Turkey's largest city late on Monday, following a tip-off, however, they left the scene without making any arrests.
Newspaper reports said the attacker, who slipped away from the scene of the attack, was thought to be of a central Asian background.
A CCTV image (above) published by the Haberturk newspaper on Monday shows the man identified by police as the main suspect in the attack.
Mourners gathered on Monday around the Turkish flag-draped coffin of one of the victims, 23 year old Yunus Gormek.