According to a copy of the first report to creditors, administrator Ferrier Hodgson said an investigation into whether the company was trading while insolvent should take place.

The administrators have also flagged an investigation into the decisions of Forge's directors in the lead-up to its collapse, including the payment of director bonuses and other entitlements.

Forge went into administration and receivership last month amid estimated debts of $A800 million. 1400 employees were made redundant as a result of the collapse, with reports of workers being owed back pay and not being able to access their tools and gear onsite after the company fell into administration.

The Perth-based group had a market capitalisation of more than $350 million a year ago and posted a $62 million profit in the 2013 financial year.

But cracks started to appear in the second half of last year after the company experienced major overruns at two of its power station construction contracts – the West Angelas (Western Australia) and Diamantina (Queensland) stations.

"Based on our preliminary investigations to date, we are of the opinion that the group may have been insolvent as early as November 2013," the Ferrier Hodgson report said.

Ferrier Hodgson said further investigation by a liquidator could result in an earlier date of insolvency being determined.

The report said the company had faced difficulty paying its creditors since at least early November and was running at a loss for the 2014 financial year.

Ferrier Hodgson said its preliminary investigations had identified the primary causes for Forge's failure as being greater contractual risks arising from the 2012 acquisition of CTEC, the company’s reliance on debt funding and low margins on contracts susceptible to cost blowouts.

A second meeting of creditors, to be held in Perth next week, will decide the future of the company and its 36 subsidiaries.