The TikTok video shows what looks like old footage of Meyer with the caption making light of the sentence.
Corrections deputy regional commissioner Ali Rei said since the sentencing, a number of third parties have posted to social media claiming to be Meyer on accounts, which have now been deleted.
"We are taking immediate steps to investigate this video," Rei said.
"I fully acknowledge that seeing this sort of content will be extremely traumatic and distressing for survivors, and we are absolutely committed to ensuring this person can cause no further harm."
Meyer's sentence has sparked protests around the country.
Protest organiser Spencer McNeil said the offensive video came up on his TikTok and appeared to be fake.
"We sent it through and they reckon it was definitely someone stirring the pot," he said.
"I think it's stupid. I don't know why people would want to go out of their way to cause more problems. It just shows there's a lot of scum out there, they just want to cause problems."