A former trainee soldier who carried out a campaign of rape on a woman by creating fake social media profiles and manipulating her into having sex with him has been jailed for 18 years.

John-Lee Osborne, 27, bombarded the woman with more than 4,000 messages over a three-month period from four fake characters he had created.

Through the fake characters Osborne convinced the woman that if she did not have sex with him, he would be kidnapped, beaten, raped and imprisoned.

Osborne claimed he was also being forced into sex with the woman – a stranger – against his will, insisting that they were being filmed and listened to by would-be kidnappers.

The former trainee sapper with the Royal Engineers was convicted of 15 charges of raping the woman following a trial at Bristol crown court.

Judge Mark Horton jailed Osborne for 18 years and ordered him to serve a further five years on licence for the “ruthless” offences. “This case represents a very disturbing development in the use of social media,” the judge told Osborne, of Aust, near Bristol.

“You used and developed applications and services available to you through the internet, social media and dark web to orchestrate what effectively became a weapon in your hands to establish and achieve the emotional and physical control of your victim. You used your actions to bully, control and eventually blackmail her.”

Judge Horton described Osborne as dangerous and said his actions were “determined, planned, malevolent”. The messages were written in individual styles for each fictional character.

“They enabled you to create a scenario in which your victim believed that you would be kidnapped, abused, beaten, raped and imprisoned if she did not submit to having sexual intercourse with you upon your demand,” the judge said.

“You destroyed her mentally. You controlled her body and mind. This is worse than violence. Violence you recover from. This victim will never recover.”

The court heard Osborne has previous convictions for battery on his mother and for using social media to harass a girl when he was a teenager.

Speaking after the case, temporary DCI Tom Herbert, of Avon and Somerset police, said Osborne’s deceit “knew no bounds”.

“He preyed on the trust his victim placed in him to rob her of her true ability to consent,” he said. “The deception was so sophisticated that she did not suspect any of the fake personas were in fact Osborne and fully believed those contacting her were real people. As a result, she genuinely felt he was in danger and had to do anything she could to help.”

The woman urged other victims of sexual assault to come forward. She said: “Don’t ever feel like you’re alone and never be afraid. There will always be someone to hold your hand and help support you through your journey. Don’t be ashamed to stand up and speak out in confidence.”