LONDON-Children as young as 14 are making thousands of pounds a week as part of a global hacking network built around the popular video game Fortnite.

The items are collected as in-game purchases but are purely cosmetic and do not give gamers any extra abilities. Fortnite-maker Epic declined to comment on the investigation but said it was working to improve account security.

One British hacker said he got involved at the age of 14 earlier this summer, when he himself became the victim of a hack. Speaking from his bedroom via a video chat, wearing a baseball cap and bandana to hide his identity, the teenager said he had spent about £50 of his pocket money to build up a collection of skins, when he had woken up to a message that changed everything.

"The email said that my password had been changed and two-factor authentication had been added by someone else. It felt horrible," he recalled.

Two-factor authentication meant his account could only be accessed by entering a code sent to an email address or app registered by the perpetrator. Like many victims, he turned to Twitter to vent his frustration. That was where he saw new accounts containing even better items on sale.

"I was approached by someone who said I could buy an account for 25p and I could clearly see the account was worth a lot more," he recalled.

"I bought it."

He knew he was playing on a stolen account but with so many others doing it online and making lots of money, he was soon drawn into the world of "Fortnite cracking".

"I was approached by a cracking team and they told me what it was and all about 'combos', 'proxies' and I guess they showed me how to crack," he said. He said they showed him where to find the vast lists of usernames and passwords published online from other data breaches over the years.

Hackers can lock out players by tying the account to their own email address. They showed him where to buy "off-the-shelf" hacker tools needed to input those credentials into the login page of Fortnite. Once inside an account, they showed him how to take it over and then sell it to the hungry online community.

He insisted that he only carried out one cracking session. But in that single day he managed to access more than 1,000 Fortnite accounts.

"It's lucky dip basically, you either get a good account or you don't. People like the rarity of the 'skins' and it's about the look of them and showing off to friends."

The hacker said he was now a middleman for other crackers, selling on accounts he knew to be stolen. In his first few weeks, he made around £1,500 and bought himself some games and a new bicycle.

He said he knew what he was doing was illegal, but his parents were aware of his activities and had not stopped him.

About 20 hackers told the BBC they were stealing the private gaming accounts of players and reselling them online. Fortnite is free to play but is estimated to have made more than £1bn through the sale of "skins", which change the look of a character, and other add-ons.

Hackers can sell player accounts for as little as 25p or hundreds of pounds, depending on what they contain.