One child in every secondary school classroom has a gambling problem or risks developing one with a possible "loss of control", a watchdog has warned.
A report produced by Ipsos and published by the Gambling Commission asked 2,559 pupils aged 11 to 16 years old across curriculum years 7 to 11 to describe their gambling behaviour.
The results found that 3.5 percent of kids surveyed - one in every 29 children - had a betting addiction or were showing signs of developing one.
The report also found that more girls (0.9 per cent) than boys (0.7 per cent) now have a gambling problem.
The study defined problem gamblers as children who gambled with "negative consequences and a possible loss of control".
The survey data identified 0.9 per cent of 11 to 16-year-olds as problem gamblers, 2.4 percent as at-risk gamblers and 27.3 per cent as non-problem gamblers.
The report said that three in ten (31 per cent) of kids were actively involved in gambling in the last 12 months, having spent their own money on gambling activities.
Many of them spent their own money on types of gambling activity that are legal or do not feature age-restricted products such as penny pusher or claw grab arcade games (22 per cent) or bet for money between friends or family (15 per cent).
More 11 to 16-year-olds spent their own money on regulated gambling activities (23 per cent) than unregulated activities which fall outside the remit of the Gambling Commission (18 per cent).
Overall, 10 per cent said they had played some form of National Lottery game in the past year.
The Commission said: "In this year's survey, whilst the headline data around regulated age-restricted products is encouraging, there is clearly a group who still struggle with gambling.
"We are committed to understanding and acting on these findings in more detail to help us, and a variety of other stakeholders, appreciate if and how young people are playing on regulated and non-regulated products, the challenges, and the wider implications."
It added: "Preventing gambling-related harm is at the heart of our work and we have accelerated our drive to make gambling even safer.
"Just some of those examples include ramping up our enforcement activity against failing operators, including those who have targeted children, clamping down hard on online slots products, increasing online age and ID verification, strengthening customer interaction requirements, and banning gambling on credit cards."
Henrietta Bowden-Jones, director of the National Problem Gambling Clinic, told The Times : "There is not enough protection of children when it comes to exposure to gambling cues . . . adverts on social media or gambling logos and ads when sports are being watched. Gambling has been normalised in an ever-increasing manner over the past 15 years since the implementation of the 2005 Gambling Act.
"[This is] a generation who no longer see gambling as something that belongs to the adult world. It is now seen as a common pastime and within reach due to the internet and to its close links to sport.
"There is an urgent need to review this exposure in the Gambling Review in order to reverse the process and protect future generations."
The Betting and Gaming Council added it enforces strict age verification to prevent underage gaming.
A study published in 2019 claimed that half of Britain's children were at risk of gambling addiction.
Some as young as three were being exposed to "lookalike" betting content in online games, the research discovered.
Youngsters are tempted to spend by "loot boxes", where players face a lottery when they buy unseen items, it found.
Each year families are estimated to be losing more than £270million to in-app purchases and video game add-ons.
In 2020, the first NHS child gambling clinic began treating addicted children who lost up to £100,000 on internet football betting and web casinos.
A report found that a teenager who got hooked at 13 plunged his father's business into bankruptcy after stealing £60,000 to fuel a six-year online betting spree, while a 12-year-old used his dad's business card to set up an account and blew £20,000 in one night's online roulette.
Dr Henrietta Bowden-Jones, director of the National Problem Gambling Clinic, which treats kids as young as 13, said: "We are talking heavy, heavy gambling in a population of young people who clearly cannot afford it."
And campaigning MP Carolyn Harris said: "These are truly shocking figures and we urgently need stronger regulation to prevent children from gambling and stop the devastating consequences this can have."
