Yvonne Graham arriving at court ahead of being sentenced to 18 months in prison

A scorned mistress put up posters claiming her businessman lover was a paedophile and embarked a on 16-month campaign of harassment when he refused to end his marriage.

Successful care-home entrepreneur Yvonne Graham, 45, bombarded timber boss Andrew Nelson and his wife Lorraine with letters and text messages exposing their secret affair while still dating him.

She put up laminated posters falsely proclaiming her current lover was a paedophile in a desperate attempt to push them apart.

The married mother-of-two sent letters telling his wife: 'Where do you think he is when you are working?' He is screwing that b***.'

But when that didn't work she sent letters to his son, 85-year-old mother, neighbours, dentist, estate agent, business associates, a school and golf club where he had been a member since 1974 - seeking to destroy his marriage and force him to move in with her.

In the worst excess she produced a second poster of Mr Nelson comparing him to a convicted paedophile, before sending letters claiming he was a thief and threatening to burn down his business and kill him.

The campaign forced Mr Nelson to stop playing golf and live like a hermit, embarrassingly taking down posters and recovering letters sent to neighbours and friends.

Jailing Graham for 18-months at Hull Crown Court, Recorder Simon Jackson QC told her: 'You embarked on an appalling campaign of harassment that made the life of the complainant and his family utterly miserable.

'You had an affair with the complainant. You believed he was going to leave his wife and form a relationship with you. You began by sending texts and cards, and you purchased a SIM card to send messages. You made out that you too had been a victim of this.

'This was a lie. There seemed no limit to the steps you would take to take some sort of perverse revenge on this man. It was an attempt to destabilise his family, in the hope that he would leave his wife.

'Posters described him as a thief, dishonest, and most worryingly, that he was a paedophile and had an interest in children, all of which were wicked, wicked lies that you perpetuated for your own selfish motivation.

'It is difficult to imagine a more damaging campaign of harassment carried out over an extended period. At one point you put up poster calling him a paedophile. It was monstrous.'

Prosecutor Richard Thompson said Mrs Graham who is married with daughter aged 11 and 17 met Mr Nelson a successful timber business owner through business contacts in 2011.

He said: 'She told him she was separated from her husband. There was a mutual attraction and they began a relationship.'

He said initially Mr Nelson's, wife knew nothing of it, but both parties partners found out about the cheating in October 2012.

Graham was arrested along with an employee in September 2015 after suspicion grew that she was behind the campaign of abuse

Mr Graham has since moved to live in Greece but they are still married.

The affair continued and she would meet him at various locations with Mrs Graham insisting Mr Nelson had told her he intended to leave his wife.

Mr Thompson said Mr Nelson was still with his wife and seeing Mrs Graham when anonymous text messages arrived making reference to the affair.

Police established the SIM card used to send the messages has been bought from a shop close to Graham's business address in Hull.

Letters started arriving at Mrs Nelson's home accusing him of having multiple extra marital affairs.

Mr Thompson said: 'The correspondence was framed as if a third party were following the couple in their affair.

It included statements like: 'Where do you think he is, when you are working. He is screwing that b***.' 'Let's hope your kids don't find out.

'I have not had this much fun in a long time.'

'He has been screwing that b*** and betraying you. I am on to them. Don't worry.'

Mr Thompson said: 'She was laying false trails. Naming herself as the person he was seeing.

'On one letter she put a picture of his wife accusing him of fathering other children including her own and referring to him as a paedophile.'

Mr Thompson said the worst excess was the production of a laminated poster of him put up around the small town of Hornsea.

It showed a picture of him and said 'he's a paedophile. Watch it if you see him near your kids!'

He said a second poster showed Mr Nelson with a picture of a convicted Hornsea paedophile on it.

It said: 'What have these two dirty pedophiles got in common. One is locked up the other is getting away with it.'

The harassment escalated with a menacing note threatening an arson attack on his business. It said: 'You would not want a fire to start, would you. Tick Tock.'

He also received threat to kill him, break his legs. He took the threats so seriously police installed a panic alarm.

By July 2014, with the police investigation in full swing, Mr Nelson had no idea who was stalking him or that Graham was monitoring his reactions.

Mr Thompson said: 'He mentioned a serving police officer who he had an earlier minor disagreement with. That officer was investigated by the police professional standards branch and for a number of months before being cleared. Mrs Graham knew of this.'

Graham, who employs 140 people as co owner of eight care homes called Fox Glove Care, appeared at Hull Crown Court having pleaded guilty to a single charge of harassment

The following May, Mrs Graham was spoken to by police but she denied being behind the harassment, she produced a photograph of hae away with Mr Nelson saying it had been sent to her.

The harassment continued with intimate details of her affair which only she knew In September 2015 suspicion had fallen firmly on Graham, who was arrested along with an employee.

'(The victim's) nephew had sent a request for information to that company, so a sample of handwriting could be obtained,' said Mr Thompson. 'The handwriting matched some of the handwriting that had been sent to the victim and his family.'

Graham denied it but the employee confessed to producing some of the documents with her handwriting. She claimed Graham told her she would take the blame if the police found out.

Mr Nelson, a successful timber importer, was initially told by the police on two occasions there was insufficient evidence to prosecute. It was only whenhe funded a £5,000 private prosecution that the police and the Crown

Prosecution Service took him seriously and took over the case.

Graham, who employs 140 people as co owner of eight care homes called Fox Glove Care, appeared at Hull Crown Court having pleaded guilty to a single charge of harassment.

The crown left charges of the file of making threats to kill and damage property by fire and doing an act tending to pervert the course of justice. The court heard she has shown no remorse.

In a victim impact statement Mr Nelson said he expected he and his wife to suffer from the harassment campaign for the rest of their lives. He said: 'I had to knock on people's doors asking if they had received letters. I cannot put in to words how difficult that was.'

He said he and his wife did not socialize losing touch with friends.

'I contemplated taking my own life. We lived like hermits. I have only just got back to playing golf - and that is early in the morning. When we can afford to move we will.'

Lorraine Nelson said in her victim impact statement she could not eat or sleep and could not concentrate on her job. She said for 18 months she stopped seeing friends.

She said she had to change her car after a letter which asked people to wave at her because she was involved in group sex.

She said 'I am an extremely private person. This has publicly devastated our lives. I used to be able to hold my head up high, but now I feel like a criminal. I hope eventually to be able to move away, but cannot because of elderly relatives.'

In mitigation Simon Godfrey said: 'When she commenced the relationship she was in a very difficult marriage. Her husband didn't work.

'Her mother was diagnosed with cancer. It was a relationship that was very much on an off after both partners became aware of it. Mrs Graham said she understood that Mr Nelson was going to leave his wife.

'When it became apparent he was never going to leave his wife she acted in an abhorrent way. She thought that in some obscure way it would destablise his marriage.'

Recorder Simon Jackson, QC, jailed Graham for 18 months imposing an indefinite restraining order prohibiting her contact with Mr Nelson and his family.

She must also pay Mr Nelson £5,000 costs plus VAT and £1,500 court costs.