Oliver Kiesanowski posed online as a woman named Rebecca and connected with at least 17 victims - eight identified and nine unidentified - in the Christchurch area between 2017 and 2023.
He obtained explicit images from those victims and then used the content to force them to send further explicit images.
Kiesanowski was found guilty on a number of charges in the Christchurch District Court and sentenced to five years' imprisonment. He was also placed on the child sex offenders' register.
Police believe there could be more victims who have not yet come forward and want to encourage any who have not contacted police, to do so.
Acting Detective Sergeant Michael Hawke of Canterbury CIB said he was pleased to see justice for these victims.
"This offender subjected his victims to protracted periods of living with stress and fear that their online activity would be revealed to their friends and family, not to mention routinely forcing them to create explicit material they did not want to.
"We hope that if there is anyone who was not identified through our investigation who has been out there living in fear, that they can now feel safe in the knowledge that this offender will be behind bars for years to come."
Acting Detective Sergeant Hawke said anyone who wanted to disclose offending of this nature to police would be heard and treated with respect.
"We know that unfortunately some of these victims don't want to talk about what has happened to them as they are embarrassed or ashamed about getting drawn in.
"But we want you to know - we know how insidious this type of offending is and how easily victims can become trapped."
How to spot this type of offending
- Meeting on one app, then being encouraged to continue talking on a different app could be an indicator.
- Inconsistencies with a profile or language, and there might be signs that English is a second language.
- Introduction of sexualised conversations.
- The other person may say that their webcam or microphone not working for video calls/chats, in a bid to avoid giving their true identity.
Advice for victims
- Avoid sending any more images or videos - even if they are threatening you.
- Remember - once you have complied with their demands there is nothing preventing them targeting you again.
- Save all the online chat, immediately take screenshots (this is important for a police report)
- Block the profile.
- Report the content to the platform (e.g. Facebook, Snapchat, PornHub) it's on and request it is removed
- Make a report to police (via 105) or Netsafe to find out what other options are available to you.
