The E.coli inquiry in Cardiff has been shown graphic images of conditions at the butcher's firm in Bridgend responsible for the outbreak.
The images show how the storage freezer in John Tudor & Son was piled up with stock.
The pictures show how dirty the equipment had become with evidence of congealed blood on machines and pieces of raw meat left on the floor.
As well as dead insects at the butchers' plant, the inquiry was told there was also congealed dirt found around machinery used for slicing and packing food.
The evidence also includes this picture of a vacuum-packing machine which was used by the company for raw and cooked meat.
More than 150 children and adults fell ill and five-year-old Mason Jones died in the 2005 E.coli outbreak. Butcher William Tudor has been jailed for a year for food safety offences.
The inquiry was guided through the pictures by Prof Chris Griffith of the University of Wales Institute, Cardiff, (Uwic) and Colin Houston from the Food Standards Agency.