THE head of the Unite union has attacked the inquiry into emails at the centre of the Falkirk vote-rigging allegations, calling it a waste of police time.

It emerged at the weekend that Police Scotland had dropped its investigation after finding no evidence of wrongdoing.

The mails - alleged to show attempts by Stevie Deans to help Unite secure a safe Labour seat for its preferred candidate, Karie Murphy - were given to police by Mr Deans' former employers at the Ineos oil refinery at Grangemouth.

Len McCluskey, Unite's general secretary, said that the decision to take no further action had "vindicated" the union's position that it had done nothing wrong.

He added: "It is shameful that the police's time has been wasted by vexatious complaints and their attentions diverted from catching real criminals."

He also defended Mr Deans, who last week was given a job by the union, saying he was a "decent and honourable man who had been smeared and hounded with a callous disregard for him and his family by those who should know better".

He added: "(This) witch-hunt has been exposed to be without foundation."

The Falkirk allegations centred on claims local people had been signed up as Labour members without their knowledge.

In July last year, Labour leader Ed Miliband accused Unite of attempting to fix the selection of the party's candidate for the 2015 General Election. But he was forced into an embarrassing climb-down months later when Unite was cleared.

Yesterday an Ineos spokesman said: "The email cache was referred to the police and the information commissioner based on legal advice to protect the company."

A Police Scotland spokesman said: "Following information received alleging misconduct by a member of staff at the Grangemouth refinery, a Police Scotland enquiry was undertaken.

"This inquiry has now concluded and there is no evidence of any criminality."