Timber giant Gunns may have traded while insolvent, administrators of the collapsed company say.
In a detailed report to creditors, PPB Advisory says more investigation is needed to determine the date of insolvency.
But the report says Gunns may have had solvency concerns six months before it entered administration on September 25 last year.
"As we are yet to form a conclusive view on the date of insolvency we are unable to state definitively whether the Gunns Group traded whilst insolvent," the report said.
"Additional investigations will be required by a liquidator (if appointed) before a view may be formed."
The administrators' "preliminary view" is that Gunns was insolvent from "at least" September 21.
But the report says solvency concerns could have existed when prospective partner in the company's proposed northern Tasmanian pulp mill, the Chandler Corporation, pulled out in March 2012.
PPB says there were also concerns in July, when Gunns announced it was relying on the support of lenders, and September 12 when lenders knocked back a request for funding.
It says it is continuing to investigate the possible use of third party funds from managed investment schemes among a number of potential breaches by directors.
The report concludes Gunns has debts of about $3 billion and recommends the company be liquidated.
It says lenders owed $446 million are unlikely to be paid in full and unsecured creditors owed $2.4 billion will not see any return.
Workers' entitlements totalling $10 million will be met, the report says, but the timing of payments remains uncertain.
A second meeting of creditors in Launceston next Tuesday will determine whether the company should be wound up.