The Engineering Printing & Manufacturing Union says heavy debt incurred after a family split may have triggered the receivership of the Yarrows Taranaki bread factory.
Yarrows has called in receivers to its plant at Manaia, near Hawera.
The EPMU says the Subway chain - which Yarrows supplies - wanted that the company to set up a factory in Sydney before the recession began.
The EPMU says the sons of Noel Yarrow fell out after died three years ago, and one had to buy the other's share.
It says this added to the company's financial problems.