A “malicious” psychological abuser from Harpenden who made up a fake ex to stalk his new girlfriend has been jailed for 18 months.

Former British Transport Police officer Steven Campbell, 28, of Northfield Road, sent insulting and pornographic emails and Facebook messages from ‘Nicola Cole’ to both to himself and to his partner.

He destroyed his new girlfriend’s self-confidence, St Albans crown court heard on Thursday, and she was driven to anti-depressants and counselling.

Prosecutor Andrew Howarth said the stalking began in October 2014 with a request by ‘Nicola’ to go for coffee with Campbell.

In a message to the victim, ‘Nicola’ said she still loved and missed Campbell and was “surprised [he is] not with someone prettier and slimmer”, claiming to now earn £60,000 a year plus bonuses in the financial services industry.

The victim responded by asking ‘Nicola’ to leave them alone, but it did not stop, and on the victim’s birthday, ‘Nicola’ sent cropped photographs of a naked woman and a male penis - the explicit content then continued throughout the abuse.

Before Christmas 2014, she told the victim that she had worn Campbell out having sex in their home, supposedly proving it by sending a picture of their Christmas wreath, making the victim “petrified and physically sick”, according to Mr Howarth.

Cambell was caught out when a police officer saw the reflection of a man in a hoodie in the corner of the picture.

Campbell was arrested on 15 January 2015 and his computer was seized. He told the police that ‘Nicola’ had studied Finance and Administration at the University of Strathclyde, but no Nicola Cole had graduated there.

More than 200 hours of police time was wasted trying to find ‘Nicola’, with 208 people contacted on the Electoral Register.

After Campbell was bailed, he returned to live with the victim and continued to communicate with her via ‘Nicola’.

But, on 28 March 2015, Campbell’s laptop was seized by the police, and ‘Nicola’s’ accounts through TOR and Proxy Servers, and the pornographic images sent to the victim were found.

The police also found two of Campbell’s exes in Scotland who had a similar experience from a woman called ‘Megan’.

Campbell pleaded guilty to aggravated stalking and he has resigned from the police. The victim is in a new relationship.

Defending, Nick De Freitas mitigated for Campbell: “He was off sick during this period of offending, he was on anti-depressants and was in a very low place, it started because he wanted to make his girlfriend jealous, he wanted her to know how good he was.

“To say it spiralled out of control is an understatement.”

Mr De Freitas noted he has no previous convictions, now has had cognitive behavioural therapy, and has concerns about prison as a former police officer.

Jailing Campbell, Judge Jonathan Carroll told him: “You engaged in the most malicious, nasty, manipulative form of controlling psychological abuse that I have come across.”

He said it was a “gross, extended breach of trust” in a relationship, driving the victim to “utter despair”, and turning “an innocent person’s life upside down”.

The judge believed he committed the crime to make her dependant on him: “She was in fear and became so frightened she needed you to walk her to her car.”

He added: “There was a deep seated calculation in you to destroy her self confidence and promote her dependency on you.”

The judge made an indefinite restraining order banning Campbell from contacting the woman, and commended the officer who had seen the reflected image for his thoroughness in the investigation.