Footage of gunman in Santa outfit prowling through Istanbul club

Footage from inside an Istanbul nightclub has shown the Santa costumed gunman who opened fire on New Year's Eve killing at least 35 people.

The CCTV, posted to Twitter by Turkish journalist Urun Dirier, appears to show the alleged shooter stalking through the Reina club as he stepped over debris after opening fire at patrons.

The man is wearing a white jacket and a bobble hat and is holding what appears to be a weapon before walking out of frame.

He appears to drop something on the ground before walking away.

Around 500-600 people were thought to have been in the club when the attack happened around 1:15am, broadcaster CNN Turk said.

Some jumped into the waters of the Bosphorus to save themselves and were rescued by police.

Istanbul has been the target of a series of recent attacks by Islamic State and Kurdish extremist groups.