Reports say he was found in the Esenyurt district of the city
The man suspected of carrying out the New Year's Day shooting at an Istanbul nightclub has been arrested, according to local media.
Abdulkadir Masharipov is believed to have opened fire at Reina nightclub, killing 39 and wounding 69 others.
According to local TV, the Uzbek national was arrested after a raid on a home in the Turkish capital's Esenyurt district.
Masharipov underwent medical checks before being taken to a police station for questioning, Hurriyet newspaper reports.
At the time of the massacre, Reina nightclub was packed with up to 600 revellers celebrating the New Year.
CCTV footage showed a man shooting dead policeman Burak Yildiz and travel agent Ayhan Arik at the front of the venue, before entering and firing 120 bullets at party-goers.
Witnesses described diving under tables during the attack, while one reveller told how she had to lift dead bodies off her to escape the building.
People from Lebanon, Saudi Arabia, Israel, Iraq and Morocco were among the victims.
Islamic State claimed responsibility for the atrocity, saying it was revenge for Turkish military involvement in Syria.
The arrest comes almost a fortnight after Turkey's deputy prime minister said security forces had identified the potential whereabouts of the nightclub attacker.
Veysi Kaynak said the "specially-trained" attacker carried out the shooting alone, but was likely part of a "well-formed" larger cell.
While CNN Turk reports that five people - including the suspected attacker - were detained.