An investigation is under way over hundreds of missing polling cards for the Scottish independence referendum.

With polls still too close to call, every single vote could be crucial.

But The Scottish Mail on Sunday can reveal that hundreds of polling cards are still unaccounted for and, in one town, there are entire streets which have not received them.

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Counting: Hundreds of voters in the Scottish referendum claim they have not been sent polling cards

Residents in Strathaven, South Lanarkshire, fear their votes may have been 'stolen'.

The local authority is now carrying out an investigation but yesterday blamed a third party contractor, which produces the cards, and confirmed it had received 160 call-ins from worried members of the public.

But resident Irenee O'Neill, who lives in one of the affected streets, said: 'We know the numbers are much higher. There's been a fundamental failure and the disappearance of so many is highly suspicious. Anyone with our polling cards could vote in our names and we can't do anything to stop it.'

Another local, Patricia Frame, who previously served as a polling station clerk, said: 'I've never known cards to go missing on this scale before. Maybe one or two, here and there, but not so many in one area.

'It's very peculiar and it must be thoroughly investigated to make sure they haven't fallen into the wrong hands.'

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The disappearance comes after people reported on social media around Scotland that they have either been sent two polling cards in error or still have not received any with only four days to go.

Two weeks ago, it emerged that children as young as three had been registered to vote and received polling cards in East Ayrshire.

Yesterday, after initially saying only 36 people were affected, the local authority issued an assurance that anyone registered on the electoral roll could still vote.

Aileen Knudsen, South Lanarkshire's depute counting officer, said: 'We take every incident of non-delivery very seriously. Registered voters are reminded that they do not need a poll card to vote.