Henry Curteis, whose autobiography encompasses the worlds of politics, business, and the paranormal, claims that MI5 bugged phones, tried to infiltrate the local party, and the State intercepted UKIP's mail in Shrewsbury.
He says that, exhausted at the end of the campaign – he came fourth in the Shrewsbury & Atcham seat with 1,620 votes – he went on a long holiday to Italy, only to discover somebody had been sent to tail him.
His experiences contributed to a decision to withdraw temporarily from politics.
"I wanted all the people who were being paid to follow me around, even now on holiday, to go away," writes Mr Curteis, a businessman and entrepreneur from Shrewsbury.
"And so for the next two years I kept very quiet, going nowhere, meeting no one and doing nothing.
"I wrote on websites and visited chat rooms advocating that Britain should not adopt the Euro, and should withdraw from the EU. That was it. By which time I had sent the security services well and truly back to sleep."
Mr Curteis' book is called "Angels & Devils – My Extraordinary Life" and tells how he started a jewellery company near Ellesmere which expanded to become the largest jewellery manufacturer in Britain.
Explaining the genesis of the book, he said: "A friend of mine, Dickie Major, passed away three or four years ago. He was one heck of a character. I thought I really ought to write down stories about him and about what we did together. And then the company Curteis Ltd asked me to write the history of the business.
"A lot of the people working there had no idea of the history of the company, which started in the attic of the house making gold and silver chain."
As his hands-on role in the company faded, he became increasingly active in politics, and started writing for UKIP and Nigel Farage, producing leaflets which raised the profile of the party, one using a Dad's Army theme being a particular hit.
One Shrewsbury activist, he says, was Christopher Bovill, who had been approached by a strange character on the streets of Shrewsbury who offered him what he described as a bag of cash containing what he estimated was about £5,000.
"It was not the last attempt by MI5 to penetrate our 'cell.' Our phones were all bugged. We had a fault and no less than four BT men turned up at the house in Whitehall Street where I then lived."
He spent £50,000 in the pre-election period on printing four million leaflets and two thousand posters, headed "EU're trapped," and expected them to generate a return for the party of at least £100,000. However, nothing came back.
Mr Curteis tells in the book how a few weeks after the election he and Dickie Major were playing a doubles match at Shrewsbury Lawn Tennis Club, and after the game they had a drink with the opposition, one of whom worked at Shrewsbury Post Office.
Recognising them as being from UKIP, the postman asked them if they wanted to know what happened to their mail, and told them: "We were told not to send it out to you, and we kept it in the office. Two men from the Ministry came and removed it all. There were seven mailbags full."
Mr Curteis writes: "There went my £100,000, which would have funded the next campaign and the next...
"Under an obscure law called The Enemy Aliens Act from 1914, the government can remove any item from the mail it chooses, without any need to go to court and get an order.
"We had become 'enemy aliens' for trying to fight an open political campaign to get Britain out of the EU."
He later rejoined the Conservative fold.
Another chapter tells of spiritual events he witnessed, and strange happenings at the family home near Ellesmere, ever since he was a child, through the presence of trapped souls and demonic spirits, with the upshot that the property was swept by a team of Christian exorcists.
He also recounts struggles with bureaucracy surrounding his Philippines-born children, with one passport problem melting away when his appeal was heard by the British Consul Joanne Finnemore Crorkin who, it turned out, came from Oswestry and went to Oswestry Girls High School.
Mr Curteis says his book is available as an ebook on Kindle, and in print (price £11.99) at Pengwern Books in Shrewsbury, and at the British Ironwork Centre at Oswestry.