Colliers head Paul Powderly quizzed on how Pat Seears came to be paid $1 million

Under questioning at an ACT parliamentary inquiry about why Colliers had suggested up to $1 million, Mr Powderly said Colliers' first draft had suggested $296,000, but the figure had changed in discussions.

Mr Seears owned the head lease on the boat hire, and subleased the business to his estranged brother, Jim Seears, who operated the paddle boats with his wife. Jim Seears was paid $575,000 for his business. Pat Seears was paid $1 million.

The land agency received two valuations early in 2015 which put the value of Pat Seears' lease at $50,000 and $100,000. In November, Colliers did a new valuation, saying the lease was worth $438,000 plus a compensation premium of $500,000, recommending a payout of $900,000 to $1 million.

Auditor-General Maxine Cooper was highly critical of the Colliers valuation, which she said made no explanation for the compensation figure and contained anomalies. As justification, Colliers had pointed to two Yarralumla lakeside blocks which sold for $1042 a square metre and $1387 a square metre. Colliers had judged the Seears lease more valuable and pegged it at $3000 a square metre. It had then used a rate of $4000 a square metre in its calculation of value, for reasons that were not explained. Dr Cooper dismissed the Yarralumla comparison as "almost meaningless".

Mr Powderly said Colliers had sent a draft valuation on November 23, 2015, suggesting $296,000. Quizzed by the Liberals' Vicki Dunne on why that figure became $438,000, Mr Powderly said he could not speak for the hea head of valuation at Colliers, Rob Rixon, who had done the work, but Mr Rixon had judged the Seears lease more valuable than the Yarralumla comparisons.

"His initial assessment was $296,000 and he increased that to $438,000 in the process between draft and final ... it wasn't my job necessarily to query his justification, he came up with his assessment."

Asked why Colliers had shifted from $3000 a square metre to $4000 a square metre for the Seears lease, Mr Powderly said, "The conversation between draft and final was a conversation between the LDA and what they were doing with the other property and that obviously must have influenced the decision to change it by $1000 a square metre which added a hundred and something thousand to the property. In many instances, we issue draft reports because there is always an area for people's interpretation of evidence and their opinion."

As for the compensation payment, Mr Colliers said the land agency had asked Colliers to consider compensation so Mr Rixon had looked at what NSW paid in projects such as Westconnex. He had been told that premiums in the range of $50,000 to $500,000 were paid when land was compulsorily acquired.

A redacted version of the Colliers valuation has now been released. It says that it would be "not unreasonable to pay a premium" given the property was essentially being compulsorily acquired. It doesn't mention paying $50,000, only saying, "It is not unreasonable to pay a premium over its straight real estate value for the above heads of compensation of up to $500,000."

Labor's Bec Cody said the alternative, a drawn-out court process, could cost at least $500,000, to which Mr Powderly agreed that $500,000 in court costs was possible, it was perhaps excessive, and the issue was more about not holding up a public project for four years. "That's right", Ms Cody agreed.

Mr Powderly also rejected a finding by Dr Cooper that he had emailed the valuation directly to land agency head, David Dawes, on November 30, 2015. Mr Powderly said the claim was wrong. The valuation was done and sent by Mr Rixon.

Mrs Dunne asked him how he responded to the criticism from Capital Valuers, the experts who advised Dr Cooper, that the Colliers valuation "does not stand on its own, cannot be relied on without further review of a number of anomalies .. and that the final ascribed value lacks evidence and methodology and has not been justified".

While the auditor's criticism was wide-ranging, Mr Powderly suggested it related only to the compensation figure. "Obviously, they're talking about the difference between the $496,000 and the recommended range [$900,000 to $1 million], and as I said before, getting governments to release information about confidential compulsory acquisition things is near on impossible and if i could have had that information inserted into the report then maybe those comments wouldn't have been provided."

Colliers had been given just seven to10 days to do the work, he said.