Police probe claims pro-UK campaigners took illegal postal vote 'tallies'
Claims that pro-UK campaigners breached electoral law by counting postal votes ahead of referendum polling day will be formally investigated by police.
Scottish Tory leader Ruth Davidson said Better Together agents took "tallies" of postal votes at sample openings held before the count.
Election rules state the results of these openings must be kept secret.
The Crown Office has now instructed police to conduct an investigation into the complaints.
The allegations surround comments made to BBC Scotland by Ms Davidson about 45 minutes after polls closed in the independence referendum on 18 September.
Ms Davidson told the Scotland Decides programme: "We have had people at every sample opening around the country over the last few weeks... and we have been incredibly encouraged by the results from that.
"Going into today, going by the postal votes that were cast, our side would have had a lead and I think that we have a confidence, I hope a quiet confidence, that the quiet majority of Scots have spoken today."
She said postal votes were not counted until after the polls closed, but added: "Different local authorities have had openings around the country. It is illegal to discuss that while any ballot is ongoing, so until 10 o'clock tonight no-one could talk about it.
"But there is people in the room that have been sampling those ballot boxes as they have been opened and they have been taking tallies and the reports have been very positive for us."
Speaking on the BBC's results coverage, Humza Yousaf, the Scottish minister for external affairs, also made reference to indications from "postal ballot sampling".
He told the BBC's Huw Edwards: "The intelligence we're getting is that in those die-hard, traditional Labour areas actually the Yes campaign is starting to break through quite strongly.
"That's initial postal ballot sampling, all the caveats thrown in, etc., etc.."
The SNP said Mr Yousaf was referring to sampling of postal votes after the ballot had closed.
Earlier sample postal vote openings, which were attended by agents from both campaigns ahead of polling day, were held to confirm that personal identifiers - the date of birth and signature - on the postal ballots matched those held on official records.
The ballot papers were supposed to be kept face down when postal voting packs were opened so postal ballot agents and observers were unable to see how people had voted.
A Crown Office spokesperson said: "We can confirm that Crown counsel has instructed Police Scotland to commence an investigation into alleged breaches of Schedule 7, Paragraph 7, of the Scottish Independence Referendum Act 2013."
The act states it is an offence to "attempt to ascertain at the proceedings in connection with the receipt of the ballot papers the outcome for which any vote is given in any particular ballot paper or communicate any information with respect thereto obtained at those proceedings".
Anyone breaching the law could face up to 12 months in prison or a fine of up to £5,000.
The Scottish Conservatives said they were unable to comment but the BBC understands there was a telephone conversation between Ms Davidson and the police on Friday.
Party sources said there was "no suggestion she was accused of doing anything wrong".
Complaints were initially made to the Electoral Commission, which said it had brought them to the attention of police.
A spokesman for Police Scotland said: "We can confirm that we have been instructed to commence an investigation into alleged breaches of Schedule 7, Paragraph 7, of the Scottish Independence Referendum Act 2013.
"Police Scotland will not comment on anyone who may or may not have been spoken to or interviewed as part of any ongoing investigation."