A council which gave away a building it spent £500,000 on for free got rid of key paperwork about the controversial project.
That is one of a series of damming findings by investigators looking at how Broadland Council surrendered the lease of the EcoCube centre on Rackheath Industrial Estate for nothing.
It spent £500,000 in 2012 on leasing and equipping the centre to train schools and firms in green skills.
But the building was under used and in 2017 the council surrendered the lease to the builder and landowner, Tilia Properties, for nothing.
A report, which will go before councillors on the Overview and Scrutiny Committee on Tuesday, found the council's handling of the project was "inadequate".
Investigators could not find key documents including the business case, completion statement or engineer's report.
There was also no detailed record of what happened to the equipment which the council had bought for the centre.
The lack of documents meant it was "unclear" why the council got involved in the project, how it was founded and how it was managed. Emma Hodds, the council's monitoring officer, said she had spoken to people involved about the business case but no record of it could be found.
The report was also scathing of the way the council took the decision to get rid of the building.
Its solicitors, nplaw, did not tell it about an option in the contract which meant it could have sold the lease to Tilia Properties and recover some public cash - rather than surrendering it for free.
And that decision to give up the lease was made on "incomplete and inaccurate" information, the council report added.
The councillor who approved the decision did not have the authority to do so because the value of it was more than £500,000. He only had authority to make decisions up to but not beyond that amount.
A spokesman for the council said it would not put them off commercial ventures in the future and it would learn from the lessons recommended in the report. He added the authority was publishing the report to show it was transparent.
Work on the report began in August 2018 but was delayed by a disagreement about its initial findings.
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