Police say a "person of interest" in the brutal murder of a Wellington heavy metal band member died a few weeks after the killing.

The body of Matthew John Hall, 35, was found in his Johnsonville flat on February 15.

An autopsy showed he died of multiple stab wounds following a "ferocious" attack while he was in bed.

Detective Senior Sergeant Dave Thornton told the Stuff website the man was hit by a train on March 5. His death was not considered suspicious and was referred to the Coroner.

The man was also involved in the metal scene in Wellington, he said.

He did not refer to the man as a suspect but said he was a "person of interest" in the case.

"We are continuing to run a large homicide operation and I remain confident that we will find those responsible for Matthew's brutal murder," he said.

Police earlier released CCTV images of Mr Hall at Woolworths supermarket in Johnsonville - about 1.1km from his address on Broderick Road - the evening before he was found dead.

Mr Hall worked as a consumer consultant for Capital and Coast District Health Board's alcohol and drug services and general adult mental health services.

He was the lead singer in death metal band Backyard Burial and went by the stage name "Blaps Warmonger".

The band was formed by a group of school friends in Lower Hutt in 1998.

Police said anyone with any information should phone 0508 BRODERICK.

- NZPA