Nearly 90 percent of online retailers tested offered violent video games to children who were under 18. Games that were purchased included Manhunt, Grand Theft Auto, Godfather and Hitman, all of which are rated 18 and over because of violent content.

Welsh Heads of Trading Standards (WHOTS) conducted the investigation. Six local authorities used volunteers between the ages of 12 and 16, to purchase 18 -rated video games online.

Out of 44 tested purchases attempted, 38 sites went through with the transactions.

‘This survey shows how easily children can gain access to age-restricted, violent video games," said Lee Jones, acting head of Trading Standards. ‘Traders who use auction sites and accept postal orders as payment have no method of determining whether the person they are selling to is aged 18 or over."

Brandon Cook, the institute’s lead officer for age-restricted sales, said that a number of companies run age checks on customers for online retailers, which are "very quick and relatively cheap."

Companies selling products online have "a responsibility to make sure they have methods in place to avoid breaking the law by making under-age sales," said Cook.

"If traders cannot be sure the person they are selling to is over 18, then they should not be selling."

Those found selling violent games to minors can face a fine or up to six months in jail.