The OFT said it is investigating a number of "free" web and app-based games with concerns over additional costs from add-on features.
In March, ITV News spoke to Danny Kitchen and his mother Sharon. Danny racked up a £1,700 bill in just a few minutes by unwittingly buying add-ons for a zombie game on his parents' iPad.
More top news
Rio Ferdinand has hit back at Kick It Out's criticism of him by labelling the anti-racism organisation as 'pointless'
When Alison Powell's four-year-old Labrador Missy would not stop sniffing and pawing her, she knew it was more than simple canine affection.
Police have confirmed that six arrests were made as part of their operation for the Arsenal v Galatasaray Champions League match