The number of children and young people linked to murders and manslaughters using knives has risen by more than 75% over three years, an investigation has indicated.

Channel 4’s Dispatches found the number of police recorded offenders aged under 18 committing homicides using a knife or sharp instrument rose by 77% from 26 to 46 from 2016 to 2018.

The analysis was based on Freedom of Information request responses from 29 out of 43 police forces about the age of offenders recorded as carrying out knife and sharp instrument offences.

It also found that during this period the number of police recorded offenders aged under 18 committing rape and sexual assault with a knife rose from 24 to 33 and robbery with a knife increased from 656 to 999.

The programme said a police recorded offender is where there is an offender linked to the crime resulting in an arrest, caution or community outcome.

Dispatches also found there has been a 93% rise in the number of children aged 16 and under being treated for stab wounds in England.

An analysis of NHS Digital data by the programme found the number of children aged 16 and under being treated for assaults by sharp objects rose from 180 to 347 between 2012-13 and 2017-18.

Its said that 76 people were reportedly stabbed to death in the capital out of 306 across the UK as a whole last year, including 23 children.

The programme, Britain’s Knife Crisis: Young, Armed And Dangerous, is fronted by former Metropolitan Police Commissioner Bernard Hogan-Howe and airs at 8pm on Monday.

“One of the big challenges underpinning is the reality that for too many young people, particularly in our big cities, carrying a knife now feels normal.”

Lord Hogan-Howe, who retired from the Met in 2017, called for the appointment of a new “knife crime tsar” to “get a grip on the crisis”.

He said: “It’s important to focus attention on the exploitation of children in socially deprived areas.

“We need to increase police numbers in these areas and reduce the drug supply into the UK and its distribution including by county lines.

“Something law enforcement and government have failed to do.

“I just don’t see anybody getting a grip of this crisis. The government needs to appoint somebody who is going to lead it day after day.

“Call it a ‘knife crime tsar’ if you like, but somebody who is going to make sure we get knives off the street and save lives.”

Lord Hogan-Howe also called for increased interception of Class A drugs, increasing police numbers by 20,000, improving technology and building trust in local communities as part of urgent measures to reduce knife crime.

Policing minister Nick Hurd told the programme an extra £460 million is being invested in the police system this year which will be used to recruit at least 2,500 more officers.

But Lord Hogan-Howe told ITV’s Good Morning Britain the proposed number of new officers was “too few”.

Bernard Hogan-Howe
The programme is fronted by former Metropolitan Police commissioner Bernard Hogan-Howe (Stefan Rousseau/PA)

Mr Hurd added: “This is a massive challenge for our policing system and therefore a big priority for me as policing minister to make sure that our police system has the resources to invest in upgrading our technology.”

“One of the big challenges underpinning is the reality that for too many young people, particularly in our big cities, carrying a knife now feels normal.”

The show also used undercover filming to capture a 17-year-old girl being allowed to buy the knives in Asda and B&M without being challenged her on her age or asking for ID.

It being illegal to sell a knife with a blade longer than three inches to anyone under 18 but experts say girls are used by gangs to buy them, the programme said.

B&M, which was fined £480,000 in September last year for selling knives to under-age children, told Dispatches it takes “every precaution to prevent the sale of knives to under-age shoppers”.

The company said the checkout worker filmed by the show had received training on Challenge 25 in the previous 12 months and had therefore been suspended pending disciplinary action and further training.

It added: “We have had 104 test purchases in the last 12 months by Trading Standards for age restricted products, with a 100% pass rate.”

Asda told Dispatches it took its “responsibility as a retailer very seriously”, had “strict processes” around knife sales and regularly trained staff on its Challenge 25 policy.

It added: “On this occasion we got it wrong and have conducted a full investigation into what happened.”