A GROUP of fishermen convicted of breaching fishing quotas during last year's "black fish" operation are in line to receive millions of pounds in damages because the Scottish Government failed to follow due process, the Sunday Herald has learned.

Around 20 herring and mackerel fishing skippers – a large number of the Scottish fleet – were last year fined and forced to return money running to hundreds of thousands of pounds each for their parts in "black fishing" in the early 2000s. This saw thousands of tonnes of fish illegally landed and channelled through three warehouses in Peterhead and the Shetlands.

But the money is now set to start moving in the opposite direction after two of them – Fraserburgh father-and-son team Ernest and Allan Simpson, who share a boat called the Christina S – won a case in the Court of Session in Edinburgh against the Scottish Government last week. They are each expecting to be awarded damages of several hundred thousand pounds.

Since all the fishermen appear to have been treated identically by the Government, the decision is likely to prompt a raft of claims.

The case concerned a move in 2007 in parallel to the criminal investigation by Marine Scotland predecessor the Scottish Executive Environment and Rural Affairs Department (SEERAD) to allot restricted quotas to the suspected fishermen. SEERAD told them what tonnages of fish they were suspected of having caught, but refused to provide sufficient evidence.

The Simpsons spent the next four years trying to get the Government to produce the evidence, including submitting requests under Freedom of Information legislation, but were refused at every turn. When the criminal case was brought in 2011, they were charged with having taken a lower tonnage of fish, to which they pleaded guilty. They were each fined £65,000 and had more than £700,000 in illegal income confiscated between them.

Lord Uist last week concluded that SEERAD/Marine Scotland had breached the principles of natural justice and the European Convention on Human Rights.

He said: "The petitioners were not provided with the full evidence on which the decision was based, and so were not given an opportunity to comment on or contradict it, before the decision was made.

"In my view it follows inevitably from that, that the decision was not reached in a fair manner. The failure of the respondents to give the petitioners the opportunity to see and challenge the evidence against them was to the material prejudice of the petitioners and in my view vitiates the decision reached."

Michael Wells of the Alistair Dean Law Practice in Edinburgh, who acted for the skippers, said: "The door is clearly open now - This is potentially significant."

He said his clients were "rightly criticised" at the time of the convictions for breaching the quotas, but "this shows that it was not as straightforward as it seemed".

Wells acknowledged that some people might think the decision counter-intuitive, but pointed out that his clients had been punished twice for their wrongdoing. "The decision has to be seen in that context," he said.

Ernest Simpson, 65, said the case was being watched by his colleagues in the fishing industry.

He said: "We felt we were treated very unfairly and the judge has clearly recognised that."

A Scottish Government spokesman said: "We have received the judgment and are considering next steps."