One concerned parent told the Herald his 13-year-old son's school friends were betting on skins through Steam, the hugely popular marketplace owned by Valve.
"A friend of a friend has bet $200 and won $2000," Auckland father Iain Rea said, with money being withdrawn through Paypal.
"[My son] seemed to think it was quite widespread. It came up because he was talking about what to give to a mate for a birthday present and he said, 'well he'll probably just want a gift voucher for Steam', and then it came up, 'what do you do with that?', 'well you gamble with it'.
"I was surprised. That's a new one on me, that certainly seems like there's been a way found around the gambling laws."
The Problem Gambling Foundation said the "gamblification" of online gaming was growing.
"We have noticed with many of these games that the terminology and imagery used relates to gambling," spokeswoman Andrée Froude said. "This 'gamblification' of games normalises gambling for young people.
"It is important that young people and parents are aware of this crossover with gambling and gaming and the risks associated with it."
It was concerning that children were able to easily circumvent the R16 and R18 age restrictions on gaming and gambling sites, she said.
Parents had contacted the foundation with concerns, she said.
Martin Crocker from Netsafe said it was "no big surprise" that teens would place bets on online games.
"Unlike say horse racing or sports betting, Counter Strike is something that young people probably understand better and therefore would be more likely to have an opinion on the outcome of, and therefore could be drawn into gambling on it."
Young people would understand the competitive nature of such computer games, Mr Crocker said, and the value of tradeable virtual weapons.
"But having young people in an unregulated gambling space is not something that anybody would want to promote, and the online safety industry sees quite a lot of fraud around the trading of those items and scamming young people out of those items, so it's a pretty negative space often as well."
Online gambling was difficult to restrict, Mr Crocker said, with "no mechanism enforcing [age restrictions] on the internet".
The DIA said it was not illegal to bet over the internet if the operator was based overseas. However, the Government was trying to get to grips with underage online gambling.
A DIA spokesman said: "Monitoring underage gamblers in today's environment of hand-held mobile technology is extremely difficult and parents need to monitor their children's online activity."
"The Government is currently considering a number of recommendations about internet gambling in relation to sports and racing betting from the Offshore Racing and Sports Betting Working Group which reported in October 2015.
"The Government will also announce soon the next steps around a broader gambling review - focused primarily on Class 4 gambling but also looking at some issues around online gambling, which will pick up on some of the issues raised in your inquiry."
Advice for parents
Keep track of which websites your child is visiting.
Set and enforce clear rules about what kinds of sites are allowed and what kinds are not.
Install software that blocks access to online gambling sites.
Talk to your child about the dangers of online gambling.
Make sure computers are in common areas, and not in your child's bedroom.
Source: TechAddiction
