Administrators of Forge Group have said the engineering company may have been insolvent three months before it collapsed.
The allegations are contained in a report to Forge creditors in which Ferrier Hodgson recommends the company be wound up.
The report said further work needed to be done by a liquidator before any potential claims could be made against directors over insolvent trading.
Forge called in administrators on February 11 after ANZ Bank withdrew its support. It has debts of about $800 million.
More than 1500 employees were thrown out of work with unpaid wages and entitlements.
Investors first officially learned of Forge's project blowouts last November.
"Based on our preliminary investigations to date, we are of the opinion that the group may have been insolvent as early as November 2013," Ferrier Hodgson said.
"As our investigations are preliminary in nature, the relevant date may change and will be determined when we, or an alternative liquidator is appointed and a further detailed review and investigation is completed."
The administrator said there were defences available to Forge's directors because of efforts to restructure the group and secure capital.
Ferrier Hodgson blamed Forge's collapse on the acquisition of power station contractor CTEC, relying on debt funding for acquisitions and working capital, and low contract margins.
Forge's creditors will next meet on March 18.