In the week that the Home Office has launched a new initiative with retailers to ensure that knives are sold responsibly, illegal knives have been found on sale through eBay.
On 9 February, Watchdog researchers reveal how they bought five knives on the eBay website - including flick knives, a stealth knife, and a dagger disguised as a pen - all of which are illegal to sell or carry in the UK.
Selling offensive weapons
Alf Hitchcock, deputy assistant commissioner of the Metropolitan Police, and the leading national police expert on knife crime, tells Watchdog: "I find it quite shocking that a retailer, and a responsible retailer at that, would be selling offensive weapons.
"Clearly in this day and age we know that the public are very concerned about knives on the street, and retailers should be doing everything they can to stop it."
The knives - which all cost less than ten pounds - were sold by United States sellers through eBay's site in the UK.
eBay has a moral responsibility
Talking on the programme, Alf Hitchcock says that, although eBay may not be committing a crime by providing the marketplace, it has a moral responsibility to make sure that people are not going to get killed or injured by those weapons.
Dr Tom Illube, internet security expert, says: "When you're as big as eBay, you have the resources that eBay have, and you have the power in the market place that they have, it is your problem whether you like it or not. You set up the market, you run the market; it is your problem."
Dr Illube says the company can use sophisticated technology to ensure ads for dangerous or illegal goods can be filtered out, whether they originate in the UK, or abroad: "eBay already deals with the situation of filtering things out in certain countries and it could do that in this case as well. With the right will, they could certainly do a very good job of identifying illegal knives on their site."
Strong as steel
Watchdog researchers ordered six knives on eBay. One was intercepted by Customs. Of the rest, one stealth knife described as being "strong as steel" was made from plastic, making it more difficult to detect, and the senders of some others attempted to disguise the true contents of the packages by labelling them as "a gift", or "a prop".
Watchdog editor Rob Unsworth says: "We bought knives classed as offensive weapons in the UK - and in fact considered so dangerous that the programme team handed them over to the police."
Monday's programme will include footage of Watchdog presenter Nicky Campbell when he takes the knives to be examined by police.
Asked whether there might be a legitimate use for any of them, Sergeant Ian Lewis says he considers they could only have one purpose: "I would say injuring or maiming. There's no other reason for them. Flick knives, knives that are disguised... Would you really be taking that camping? I don't think so."
Sergeant Lewis explains that the knives will now be destroyed.
eBay has told Watchdog that these knives - some of which are illegal in the US too - should not have been available to buyers in the UK.
eBay blames a technical problem
They blame a technical problem with the filters on their US site, which meant UK users were able to see "US listings which are in clear breach of our UK policy".
They say they have developed technology to ensure that, from now on, all international listings of such items will no longer be visible to UK buyers on ebay.co.uk.
The company will be interviewed on Monday's Watchdog, but said in a statement: ""eBay is committed to ensuring that no items illegal under UK law are available for purchase on its UK site. With 17 million items available to buy at any one time and millions of new items added every day, we are constantly working to provide a safe and secure marketplace for our millions of buyers.
"Over 2,000 people are involved in helping us to keep the site safe and we invest over six million pounds every year in developing the best technology possible to prevent anything from slipping through the net. As the world's largest marketplace we don't handle items directly, so we use sophisticated technology to help us identify high risk or illegal items. For example, we look for over 400 keywords for knives alone to help prevent illegal ones from making their way onto our site.
"That Watchdog was not able to buy an illegal knife that has been listed on the UK site shows that the measures we've put in place to keep eBay members safe are working. However, we recognise that we need to do more. We are now working to close these loopholes and are generally reviewing our practices in this area."
Home Secretary Jacqui Smith launched an initiative with retailers this week to ensure that knives are sold responsibly. A number of big name stores have signed a six-point plan designed to stop the sale of knives to under-18s, and some have already taken steps to remove all knives except cutlery sets from their online shopping sites.
Watch the full story on Monday 9 February, 7.30pm, BBC One
Illegal knives sold on eBay
On 9 February, Watchdog researchers reveal how they bought five knives on the eBay website - including flick knives, a stealth knife, and a dagger disguised as a pen - all of which are illegal to sell or carry in the UK.
Selling offensive weapons
Alf Hitchcock, deputy assistant commissioner of the Metropolitan Police, and the leading national police expert on knife crime, tells Watchdog: "I find it quite shocking that a retailer, and a responsible retailer at that, would be selling offensive weapons.
"Clearly in this day and age we know that the public are very concerned about knives on the street, and retailers should be doing everything they can to stop it."
The knives - which all cost less than ten pounds - were sold by United States sellers through eBay's site in the UK.
eBay has a moral responsibility
Talking on the programme, Alf Hitchcock says that, although eBay may not be committing a crime by providing the marketplace, it has a moral responsibility to make sure that people are not going to get killed or injured by those weapons.
Dr Tom Illube, internet security expert, says: "When you're as big as eBay, you have the resources that eBay have, and you have the power in the market place that they have, it is your problem whether you like it or not. You set up the market, you run the market; it is your problem."
Dr Illube says the company can use sophisticated technology to ensure ads for dangerous or illegal goods can be filtered out, whether they originate in the UK, or abroad: "eBay already deals with the situation of filtering things out in certain countries and it could do that in this case as well. With the right will, they could certainly do a very good job of identifying illegal knives on their site."
Strong as steel
Watchdog researchers ordered six knives on eBay. One was intercepted by Customs. Of the rest, one stealth knife described as being "strong as steel" was made from plastic, making it more difficult to detect, and the senders of some others attempted to disguise the true contents of the packages by labelling them as "a gift", or "a prop".
Watchdog editor Rob Unsworth says: "We bought knives classed as offensive weapons in the UK - and in fact considered so dangerous that the programme team handed them over to the police."
Monday's programme will include footage of Watchdog presenter Nicky Campbell when he takes the knives to be examined by police.
Asked whether there might be a legitimate use for any of them, Sergeant Ian Lewis says he considers they could only have one purpose: "I would say injuring or maiming. There's no other reason for them. Flick knives, knives that are disguised... Would you really be taking that camping? I don't think so."
Sergeant Lewis explains that the knives will now be destroyed.
eBay has told Watchdog that these knives - some of which are illegal in the US too - should not have been available to buyers in the UK.
eBay blames a technical problem
They blame a technical problem with the filters on their US site, which meant UK users were able to see "US listings which are in clear breach of our UK policy".
They say they have developed technology to ensure that, from now on, all international listings of such items will no longer be visible to UK buyers on ebay.co.uk.
The company will be interviewed on Monday's Watchdog, but said in a statement: ""eBay is committed to ensuring that no items illegal under UK law are available for purchase on its UK site. With 17 million items available to buy at any one time and millions of new items added every day, we are constantly working to provide a safe and secure marketplace for our millions of buyers.
"Over 2,000 people are involved in helping us to keep the site safe and we invest over six million pounds every year in developing the best technology possible to prevent anything from slipping through the net. As the world's largest marketplace we don't handle items directly, so we use sophisticated technology to help us identify high risk or illegal items. For example, we look for over 400 keywords for knives alone to help prevent illegal ones from making their way onto our site.
"That Watchdog was not able to buy an illegal knife that has been listed on the UK site shows that the measures we've put in place to keep eBay members safe are working. However, we recognise that we need to do more. We are now working to close these loopholes and are generally reviewing our practices in this area."
Home Secretary Jacqui Smith launched an initiative with retailers this week to ensure that knives are sold responsibly. A number of big name stores have signed a six-point plan designed to stop the sale of knives to under-18s, and some have already taken steps to remove all knives except cutlery sets from their online shopping sites.
Watch the full story on Monday 9 February, 7.30pm, BBC One
Illegal knives sold on eBay