The Imlay meatworks could face prosecution as it continues to create a stink around its Heads Rd operation.
With the works' odour problems unabated, Horizons Regional Council has started a formal investigation that could lead to prosecution.
In the past week there have been more complaints of offensive smells to Horizons' pollution line - 0508 800 800. In the previous two months the meatworks owner, Affco, has been fined four times for a total of $5400.
Compliance staff rostered in Wanganui are now keeping record of the odours.
Horizons strategy and regulation manager Nic Peet said another aspect of the investigation would be formal interviews with Imlay staff, asking about the cause of the problem and what they had done to fix it.