More than seventy thousand votes in the recent Scottish elections were rejected by the electronic counting machines, with no human oversight.
The news has dismayed observers, with new First Minister Alex Salmond describing the news as "astonishing", and deeply disturbing. He told the BBC that he had been under the impression that all discounted ballots were checked by a person.
The discovery of the automatic discounting of votes was uncovered in a BBC investigation. The organisation says the Scotland Office ordered certain types of ballot papers should be automatically rejected as spoilt by the counting machines.
If a ballot had a mark in one column, but no mark in the other, the machines were instructed to count the visible vote and discard the other one. Then the ballot papers were to be filed alongside all the others.
In total, 140,000 ballots were logged as spoilt. The BBC says more than half of these were rejected by the machines, with no chance for a person to judge whether or not the ballot was actually spoilt.
Opposition MPs have piled in to denounce the set up. The Tory party condemned the Scotland Office for being slow to release the information.
Shadow Scottish secretary David Mundell said: "Rather than putting their hands up and saying 'we made a complete hash of this and we apologise to the people of Scotland', they've just continued to show arrogance and contempt, as if somehow it was nothing to do with them."
The Lib Dems chimed in, saying that a returning officer should have had oversight, and made the final decision.
The BBC investigation will be shown on Newsnight Scotland tonight (Monday 3 September).®