The Food Standards Agency said "no trace of salmonella" was found on the cooked ham batches linked to the outbreak but "other hygiene issues were identified."
– Food Standards Agency
Testing has been carried out on ham supplied to a number of butchers identified in the investigation.
No trace of salmonella has been found, but other hygiene issues were identified that led to one supplier voluntarily withdrawing certain batches of ham.
Investigations are ongoing.
Nine people have been admitted to hospital after an "unusual" salmonella outbreak which health authorities believe may be linked to cooked ham from small independent butchers.
The outbreak of Salmonella Typhimurium has led to 30 confirmed cases in England and 21 in Wales, with nine cases known to have required hospital treatment, the Food Standards Agency said.
Investigators are looking into other cases in both countries, with the first outbreak detected in Wales in August, which centred mainly on Conwy and Gwynedd.
Patients ranged in ages from seven months to 87 years.
A potential common link to cooked ham from small independent butchers has been found, investigators said.