A woman harassed for more than three years by an online stalker who turned out to be her boyfriend has called for him to be sent to prison.

Ruth Jeffery became withdrawn and depressed following a campaign waged by Shane Webber, who impersonated her online and sent photos of her naked to her friends and family.

Webber, 22, of Clifton, Nottingham, will be sentenced next month after pleading guilty at Southampton magistrates' court on Monday to a charge of causing harassment, alarm or distress.

Jeffrey received such detailed messages that she believed her movements were being constantly watched by someone unknown to her and became frightened to go outside.

"I want him to be put in prison because he has wrecked the past three-and-a-half years of my life," said Jeffrey, a Loughborough University student from West Bridgford, Nottinghamshire, who reported the abuse to police in March 2010.

"I've known him for 10 years, so in a way it feels like the past 10 years have been wasted. We were really close. We did everything together. I would tell him everything. I thought he was telling me everything."

Impersonating Jeffrey, Webber contacted others online and pretended to be sexually attracted to them. He gave out her term-time university address, leading to one man turning up at her house.

"He created an account very similar to mine and was speaking to people, making out he was me," Jeffery said.

She eventually realised that some of the detail in the messages could only be known to her boyfriend, but when he was confronted by her and her parents, he denied any knowledge of the harassment and pointed the finger at one of his friends, who was arrested and had his computer seized by police.

Webber began his campaign by setting up multiple fake email addresses, which he then used to contact Jeffery on MSN Messenger, pretending to be former schoolmates, before bombarding her with sexually explicit photos and videos. He also hacked her MSN and Facebook accounts.

He was caught in June this year, when he used Jeffery's own email account to send explicit images of her to her entire contact list, including her father. The email also directed people to search for further images of her online. Webber was traced through the internet protocol address of the computer from which the email was sent.

Jeffery, who spoke out yesterday following Webber's court appearance on Monday, said he might have been motivated by jealously.

"He dropped out of school. He doesn't have any qualifications and it seemed like he wanted to stop me from getting a degree."

She first met Webber when they were at primary school.

"Throughout the whole relationship, he was a bit controlling and possessive really. If I didn't go to see him the moment I had some free time, he would start complaining.

"I want other people to realise it has not been me [sending the photos and messages], and I want it to put other people off from doing the same thing."