Australian customers unwittingly bought pet food and maggot-ridden offcuts from some of the nation’s leading meat producers, newly released documents show.

Evidence presented to Justice Albert Woodward in a 1980s royal commission, which has only recently been made public, show Hammond Wholesale and Retail Meats sold pet food-grade meats to consumers without their knowledge.

Other companies passed off kangaroo, donkey, and other pet-food only meats, and sent low-quality scraps to be used in dim sims, according to Fairfax Media.

Meat that was described by a veterinarian officer as “rubbish and floor sweeping” and “eligible for pet food only” was also sold to consumers in Adelaide.

In the royal commission Justice Woodward said Melbourne meat company Steiger’s Meat Supply had “purchased considerable quantities of pet food which was injected into the human food chain”.

“The flesh of donkeys, goats, kangaroos, buffaloes and horses, killed in the field and without regard to any consideration of hygiene … was used indiscriminately to produce food for human consumption,” he said.

In other damning evidence on the meat industry an abattoir in the Northern Territory was described as filthy with “maggots”.

The details of the inquiry have come to light after a 20 year freedom of information battle led by Fairfax journalist Jack Waterford.

You can read more about the investigation here.