SCOTLAND'S top policeman is to look into claims of intimidation during the controversial protests organised by Unite at the homes of the Grangemouth refinery bosses.

Sir Stephen House, Police ­Scotland's chief constable, has responded to a letter from Conservative backbench MP Priti Patel to confirm that he will "look into the matter" and respond in due course.

A force spokeswoman said this was not a full criminal probe by the economic crime unit but a preliminary examination of whether or not one should take place.

It is currently undertaking the same procedure with a view to a tranche of emails and allegations, denied by union Unite, that it attempted to rig the Westminster candidate selection in the Falkirk Labour Party.

Unite's so-called "leverage ­strategy" has caused a deal of political controversy. During some protests, union members took a giant inflatable rat to the homes of some company bosses.

A sailing club, where ­Grangemouth owner Jim Ratcliffe is a member, was also targeted by protesters, as well as a hotel he owns and a restaurant he has invested in.

For its part, the Union has defended its tactics, with its leader Len McCluskey insisting bad employers should have nowhere to hide.

However, Prime Minister David Cameron branded them "shocking". Concerns led him this month to order an inquiry into union tactics to see whether or not the law needed to be changed to deal with instances of alleged harassment.

Unite has refused to co-operate with the inquiry, branding it a Tory stunt, while First Minister Alex Salmond suggested it was "almost entirely about seeking electoral advantage".

The controversy over Labour's selection procedure in Falkirk continued earlier this week when it was revealed that Linda Gow, the former council leader, who blew the whistle on the claims of union vote-rigging, had failed to get on the all-women shortlist for the next general election.

She said she was disappointed but added: "I would like to thank those members who have expressed support for me and I wish the three very high-calibre candidates the very best." They are Pam Duncan, Monica Lennon and Karen Whitefield; the winner will be chosen on December 8.

Earlier this year, a major row blew up when Unite was accused of signing its members up to the Falkirk Labour Party to ensure the union's favoured candidate, Karie Murphy, was selected as its next General Election candidate.

The union was cleared of any wrongdoing in an internal inquiry by Labour but the local party was put under "special measures", which meant the power to draw up the shortlist was taken away from it and is being conducted centrally.

A tranche of emails, now being considered by Police Scotland, appeared to suggest that the alleged tactics used by Unite were known about and, indeed, approved by Labour headquarters. It has refused to comment on them while Labour leader Ed Miliband has insisted it is now time for Labour to "move on" from Falkirk. The union has denied any wrongdoing and claimed it is the victim of a smear campaign.

A Scottish Labour spokesman said the party was delighted it now had three talented women to choose from to select Falkirk's next Westminster candidate.

l The BBC's Question Time last night came from Falkirk, where the panellists included Alistair Carmichael, the Liberal Democrat Scottish Secretary, Nicola Sturgeon, the SNP Deputy First Minister, Labour's Margaret Curran, the Shadow Scottish Secretary, and Baroness Goldie, the former Scottish Tory leader.