Police are investigating a threat against the teenager convicted of killing rising league star Luke Tipene.
The online threat to Vincent Skeen, 19, included the Head Hunters gang insignia and the message Skeen was "marked in and out of jail".
Police confirmed to the Herald on Sunday they were aware of the threat and were investigating. It has since been removed from the site.
"Police are aware of a threat made towards Vincent Skeen via social media and are making further enquiries into this," a spokesperson said.
Skeen was found not guilty of murder but guilty of manslaughter this week at his trial at the Auckland High Court.
The Ponsonby teen was charged after he stabbed Tipene, 17, with a broken bottle during a street fight in the early hours of November 1, 2014.
A Corrections spokesperson said Skeen's safety in prison was of utmost importance.
"Safety is Corrections' bottom line and we work to ensure every prisoner is placed in a safe environment.
"We will not tolerate prisoners using violence. A prisoner responsible for violent behaviour will be held to account for their actions.
"Prisoners who are assessed as being at risk of violence or intimidation from other prisoners may be placed on segregation, and managed separately from the general prison population."
High-profile Canterbury University criminologist Greg Newbold said the threat against Skeen should be taken seriously.
"It is pretty bloodcurdling and he will know about it, prison intelligence will tell him about the threat."