More than £250,000 has been ploughed into efforts to prevent a smell which often affects parts of Sudbury.
Nestlé Purina Pet Care has regularly come in for criticism for not doing enough to tackle the foul odour which comes from its plant.
Last week, nearby resident Jo Hawes said the “nauseating” pong meant she missed out on using her garden.
A spokeswoman for the firm, which makes pet food, said it had only received one odour complaint recently and had taken steps to solve the problem.
“We are committed to achieving the best possible odour control at our Sudbury factory,” she said.
“To this end, we continue to work closely with the Environment Agency as part of our on-going odour management plan.
“Since last year, we have invested more than £250,000 in additional abatement equipment to better abate emission sources, and added control software at the factory that allows us to monitor and measure our odour abatement performance with much greater accuracy.”
The spokeswoman added that the factory’s emissions complied with environmental guidelines and, after reviewing data from its abatement equipment, could confirm levels had been within regulations over the last few weeks.
“However, we remain sensitive to the needs of all our neighbours and, in line with our continued commitment to operating in harmony with our local community, we are continuing to work with the Environment Agency to reduce odours to the minimum possible level,” she added.