An image of the demo tape shows it was wrapped and had a note taped to it which reads:
''When there's nothing left to lose.
"i will firebomb your car.
''i will hack into your computer.
''i will leak trade & state
''SECRETS.
''i will hammer holes in your office windows.
''i will raise [sic] your buildings to
''the ground.
''i will bring you down.''
The announcement, and a post on social media, said the limited run of tapes would be coming to ''a wall near you''.
When asked about the note, police would not be drawn on its contents, instead issuing a statement.
''Police can confirm that the person spoken to over the weekend claimed they were a member of a Dunedin band and the item left behind related to that band,'' Detective Senior Sergeant Rob Hanna said.
''A search warrant was executed on Friday evening at an address in Dunedin but the AOS were not involved.
''As the matter is still an active investigation the police won't be commenting on the content of the note attached to the item at this stage.''
Much of the central city had been evacuated and cordoned off for hours on Friday as police assessed the threat.
The New Zealand Defence Force's explosive ordnance disposal squad was flown by helicopter to the city and destroyed the package in a controlled explosion carried out by a remote-controlled robot shortly after 5pm.
Police confirmed earlier this week they were assessing the criminal liability of the man involved.
When pressed for further details yesterday, police said they would not be commenting further until the investigation was complete.
Attempts to contact the Dunedin man behind the band were unsuccessful yesterday.