The January accident came to light in the same week the company was fined $30,000 after a meat hook went through cleaner Jason Matahiki's head at the same Rangiuru plant. Affco was convicted for health and safety breaches and also ordered to pay the worker $25,000 compensation.
WorkSafe NZ, which investigates health and safety issues, said in the latest accident, the worker had been pulling a hide from a carcass on the mutton slaughter chain when "he was caught by a moving hook and his head caught by a hock clamp".
"He was pulled along the chain for half a metre and the fixed hock release mechanism crushed the side of his head."
Workplace safety is becoming a focus of complaints by the NZ Meat Workers and Related Trades Union about Affco, with which it has an ongoing industrial dispute. Employment Court Chief Judge Graeme Colgan described the relationship between the two parties as "dysfunctional and apparently deteriorating" last year.
Union organiser Darien Fenton has said Affco NZ was signing contracts with workers who had less experience than union members and that resulted in a more dangerous environment.
Figures obtained by the Herald for the big five meat companies, including Affco, show accidents at the company have marginally increased when the numbers of accidents at the other big companies are falling.
But the information also shows a large increase in the volumes of stock being processed through its plants. Mr Leonard has also said the company has increased staff numbers from 2800 to 3600.
WorkSafe chief executive Gordon MacDonald told the Herald no companies among the main group, including Affco, had significantly more - or fewer - employee injuries than the others.