Authorities globally have warned about a sharp increase in the “sadistic online exploitation” of young people. Amid a wave of arrests, there are growing questions about how parents can identify whether their children are the victims of such crimes and how best to support families affected by them.

Offenders in this ecosystem often use threats and manipulation, court records show, coercing victims into producing imagery or livestreaming sexually explicit acts, self-harm or animal cruelty. In some cases, they have “swatted” family homes – calling in a fake threat to provoke an armed police response – as part of the pressure campaign.

Along with gaming platforms, these offenders may also target vulnerable young people who are engaging in digital spaces with questions about their mental health, sexual identity and other topics.

Jessica Pratley, a forensic and clinical psychologist with experience treating children and families affected by sexual offending, says parents and caregivers should watch for changes in their child’s functioning and wellbeing.

That could include emotional outbursts outside the norm, low mood and changes to eating and sleeping habits. For adolescents, this can include self-harming or risky behaviours. Other factors could be social changes, where children are particularly secretive about new friends including online, or increased isolation. “Parents know their kids best,” she says.

The Australian federal police has detailed some potential warning signs that a young person may be a victim of sadistic online exploitation (SOE), including:

• Signs of self-harm including carvings of symbols on their skin, bite marks and burns

• Changes in eating or sleeping habits

• Sudden withdrawal from family, friends, and/or usual activities

• Secretive online behaviour, or extended periods of use with online devices

• Use of extreme language, symbols and rejection of previously held morals

The eSafety commissioner also provides advice about how to recognise signs of sexual extortion and online child sexual abuse.

“One of the things that we often say in this space is that disclosures occur in the context of relationships,” Pratley says. She suggests parents try to have conversations with their children from an early age about their friendships, what’s happening at school and their interests.

This is echoed by Miranda Bain, director of therapy and specialist services at Act for Kids. She says parents may not realise how important their child’s online relationships are, but keeping in conversation about that side of their life can lower the barrier for disclosure.

Bain suggests caregivers could share their own experiences with the social media algorithm, assuring children that their reaction to online interactions won’t be angry or punitive. “Parents need to be able to have an open door for those conversations,” she says.

Given the young age of many perpetrators of SOE, Bain says it is also important that parents think about online safety generally and not just online risks from adults.

“There’s … lots of victims of online sexual abuse who do not know that they are victims,” she says. “They think they’ve done something in private and it’s actually out there on the internet.”

Young people often share with a friend first, and Pratley says parents should respond calmly, providing their child with their full attention and assuring them that they are on the same team.

Nina Vaaranen-Valkonen is a psychotherapist and the chief executive of Protect Children, a Finnish organisation that provides resources and support for families dealing with online child sexual abuse.

Protect Children has found that the highest risk for online sexual violence is ages 10 to 15, and Vaaranen-Valkonen says the age range is similar for victims of groups engaged in sadistic online exploitation.

Her organisation provides resources educating young people about red flags that might indicate online manipulation such as applying guilt and pressure – “If you really cared about me, you would …” and pushing boundaries – “Just one photo, it’s not a big deal”.

Vaaranen-Valkonen says children who are affected by these crimes can often feel intense shame and guilt because the act was committed online. This shame can also act as a barrier to disclosure.

“They blame themselves for not switching off the computer or ‘why did I respond’,” as they don’t understand the psychological manipulation behind the behavior,” she says.

Along with the children, Vaaranen-Valkonen says parents have sometimes faced a level of disbelief from law enforcement and other professionals because the crime can seem “too bad to be true”, she says, although authorities are increasingly aware of the challenge.

Protect Children runs support groups for parents whose children have suffered online sexual abuse – including from SOE groups. “Of course, the feeling of being alone and not being able to protect their own children is a devastating emotion to handle,” she says.

By supporting families and helping parents to understand trauma symptoms, healing is possible, Vaaranen-Valkonen says.

“Of course, we can teach children digital safety skills … but in the end, the guilt and shame is for offenders,” she says. “Some parents have done everything they could have done and still their child has been a victim.”

• In Australia, support is available at Beyond Blue on 1300 22 4636, Lifeline on 13 11 14, and at MensLine on 1300 789 978. In the UK, the charity Mind is available on 0300 123 3393 and Childline on 0800 1111. In the US, call or text Mental Health America at 988 or chat 988lifeline.org.