In a 'shocking' covert operation, two shops in Slough were found selling knives to underage teenagers - one of which included an eight-inch kitchen blade.

This morning the Slough Observer joined Thames Valley Police and Trading Standards in a secret operation which sought to test shops in the area on 'challenge 25', a policy that requires shops to ID individuals who look under 25 when buying age-restricted items.

"The offence of selling a knife to a minor - a person under the age of 18 - is a criminal offence," said Lina Johnson, Senior Trading Standards Officer at Slough Borough Council.

"I was shocked that we got sales in two major retailers who have got policies in place."

The operation saw a 17-year-old from a local college tasked with visiting several shops, intending to buy a bag of items, including a knife.

The first instance saw the girl approach the till with a knife and some fruit.

Items were scanned by a shop assistant who asked the girl for ID, and was told the girl did not have any on her.

The shop assistant shrugged and continued the transaction, removing the safety packaging and approving the sale.

Later on, the 17-year-old tested another shop, buying a knife, cling film and hand cream.

This time the shop assistant verbally asked if the girl was over 18, to which she responded "yes" and the transaction was approved.

The 17-year-old, who cannot be named, said: "I was surprised at how easy it was.

"Once I had the bag and walked off I was a bit shocked.

"An underaged person could go into a shop and get their hands on a kitchen knife very easily.

"Shops have to be checking. Even if someone looks the age but there is a slight bit of uncertainty, definitely check. Just asking or presuming is not acceptable."

"Staff don't have a clue what someone is doing with that knife once it is bought."

Police Sergeant Ricci Dolan at Slough Police Station said: "The operation is both educational and enforcement.

"Today goes to show the importance of the operation and even the larger retailers have fallen foul to the legislation, even with the policies and procedures they have in place.

"It was fairly easy for our student to purchase knives today without much challenge at all."

Going forward, the stores that failed today's tests will be interviewed and investigated as to what went wrong and what could have been done to prevent a repeat sale to a minor.

Lina Johnson added: "Enforcement is an ongoing thing but you have to keep monitoring it. Shops need to be continuously reminded.

"I think the bigger retailers do know the seriousness of it. They have spent a lot of time and energy getting systems in place, but the problem is monitoring the system."

The operation marks the end of the Knife Angel's stay in Slough, with the monument set to leave tomorrow.