There is no evidence of a crime regarding the fire that destroyed a One Nation billboard truck in Tasmania's south on Sunday night.
Tasmania Police released a statement on Thursday morning to say investigations into the vehicle fire at Shoreline Plaza, Howrah, on Sunday "have determined there is no evidence to suggest a crime has been committed".
It is most likely, Tasmanian police say, that the fire was caused by an ember from a discarded cigarette. There was no evidence of anyone near the ute when the blaze broke out, police said after examining CCTV footage.
Tasmania Police and Tasmania Fire Service were called to the fire at 5:20pm on Sunday.
One Nation Tasmanian Senate candidate Adam Lambert was in the shopping centre for about 20 minutes buying a present for a volunteer.
The car was lent to Mr Lambert by a supporter for the campaign.
Police thanked members of the public who provided witness statements.
Anyone with further information about the incident should call Tasmania Police on 131 444 or report anonymously to Crime Stoppers on 1800 333 000 or crimestopperstas.com.au
One Nation has been contacted for comment.