The Office of Fair Trading has launched an investigation into games on phones and tablets that are free to download, but could end up costing parents hundreds - even thousands - of pounds.
It follows concerns that children could be tricked into spending money on upgrades without realising the cost.
More top news
Scientists believe they have invented an ice cream that will melt slower in the sun.
There were shocks, tears and skimpy outfits at the star-studded MTV Video Music Awards in LA.
Ferry services from Calais have resumed in the wake of Sunday's blockade but passengers have been warned they face delays.