The man who prosecuted Skye Bridge protesters was denied access to the legal document which allowed the tolls to be imposed, it has emerged.
Questions remain over the controversial Skye Bridge tolls
Former Dingwall procurator fiscal David Hingston said it was "stunning" that he had not seen the licence giving bridge operators the right to charge drivers.
Mr Hingston, now a private practitioner, was speaking a year after the bridge's £5 toll was abolished.
He said that the UK Government only gave him access to certain documents.
"This was said to be because things were allegedly commercially confidential," he said.
"As a fiscal I was stuck with that evidence but as a private individual I found it stunning, frankly."
The bridge, Scotland's first private finance initiative, was opened in 1995.
It was operated by the Skye Bridge Company and financed by the Bank of America.
Within hours of it opening, anti-toll protesters were arrested for failing to pay the charge and around 130 people were later convicted in court.
In December 2004, First Minister Jack McConnell announced that the Scottish Executive was to buy out the bridge contract in a £27m deal, and abolished the toll.
Campaigners have argued that all those convicted of failing to pay the toll should now have their convictions overturned.
Skye postmaster Drew Millar was convicted for refusing to pay.
He said: "Personally, I couldn't care less if I have a criminal conviction or not.
"However, I think it would be nice not to have a record, if the government would accept that they were wrong from day one."
But a spokeswoman for the Crown Office and Procurator Fiscal Service said: "The former toll order and tolling regime have been challenged in the courts on several occasions.
"All such challenges have proved unsuccessful."
The bridge was one of the flagships of the Conservatives' policy to fund more public projects with private finance.
The Skye Bridge tolls were abolished last year
After operating costs, the Skye Bridge Company earned £30m from the tolls over nine years.
Taking into account the £27m it was paid for the bridge and the £21m it took to build it, the consortium made £36m profit.
The government had already paid £15m for the approach roads, £7m to subsidise tolls for local users.
With the purchase cost included, £49m came from the public purse.
Former government minister Brian Wilson said: "There was a perfectly good case for building a bridge to Skye but there wasn't a perfectly good case for paying for it twice and that was ultimately what the high toll option resulted in.
"At the end of the day, I don't think the best use of money in Skye or in that immediate locality, even at the end, was to buyout the tolls and to give money away to the Bank of America."
A radio documentary "A bridge too far" is on Radio Scotland on Wednesday at 1605-1700 GMT.