Nine knives and one axe were bought in the investigation

A 14-year-old volunteer was sold an axe by one retailer in the exercise, in which 22 stores were tested.

Almost half the stores surveyed by trading standards officers sold knives to the teenager.

The 10 traders involved have been warned further breaches of the law, by selling to teenagers under 16, may lead to legal action.

The other 12 retailers that did not make a sale were sent a letter of thanks.

The investigation, by Newport city council's trading standards team on 24 August, involved the 14-year-old trying to buy a knife or axe and telling the truth if asked their age.

The council said it would be carrying out a furture investigation, and will revisit the stores which sold knives in this exercise.

�5,000 fines

Councillor Ray Truman, the cabinet member for community safety, said the results were "of serious concern".

"It has shown how easy it is for youngsters to buy knives in our city," he said.

"We are determined to drive home the message that shopkeepers must ask for proof of age before selling and, if in doubt, refuse to sell.

"In future, anyone who continues to sell knives and other offensive weapons to those under 16 will be prosecuted and face fines of up to �5,000."