A source said the video was published on Monday night.
Mulitalo's relative Shanice Mulitalo said the video was in fact filmed in August - a month after he pleaded guilty to the offending.
The Herald is seeking comment from the relative and Mulitalo via his lawyer Panama Le'au'anae.
Mulitalo was sentenced to 11 months home detention for his "gross" offending against a 12-year-old girl placed under his supervision at an after-school care programme.
Judge Mary-Beth Sharp said he sent the girl graphic photos and videos of his penis and coerced her into performing sexual acts on him at a shed at an Auckland Youth Town centre.
At sentencing Mulitalo's lawyer said the offending was "profound" and his client had expressed "extreme" remorse.
He also wrote a letter of apology to his victim conveying that remorse.
After sentencing a photograph emerged of Mulitalo dressed as a prisoner at Halloween.
The photograph was posted to his own Instagram page and the caption referred to his upcoming sentencing, where an indication had been given he would receive home detention instead of going to jail.
"When y'all thought I was going in but then the game changed. #Wegood #Halloween2018, he wrote.
He included an emoji depicting someone giving the finger.
The Herald is also seeking comment from the Crown on the photograph and video.
Yesterday it was revealed a petition had been launched calling for Mulitalo to be resentenced to prison.
That petition now has now been signed by almost 8000 people.
