Nomad gang sources say missing Levin man Palmiro MacDonald is dead.
Mr MacDonald was last seen on March 23 and the Nomads claim the Head Hunters killed him and disposed of the body, Fairfax reported.
The gang's sources believed MacDonald was killed at the time of a fire at a Hokio Beach, Horowhenua, house in a confrontation with the Head Hunters over methamphetamine.
Police said the house was believed to be owned by members of the Nomad Gang.
A gang member who didn't want to be named said MacDonald's death had some members on edge.
"There's been messages some of the boys have gotten from the 88s [Head Hunters] saying that Powser [MacDonald] is dead and they're next," he said.
Police said they were "keeping an open mind" about Mr MacDonald's disappearance.
"However we can't rule out the possibility of a sinister element in his disappearance," Detective Inspector Ross McKay said.
"Police are taking a number of active steps to seek information about Palmiro's disappearance to assist in building a picture of exactly what has happened to him.
"We are very concerned about his well-being given the time since he was last seen, the lack of contact from him and rumours we are aware are circulating in the community.
"Anyone with information can contact Central District Police on 0800 677 256, or call anonymously via Crimestoppers on 0800 555 111.