Twelve Lewisham children have been shot with a stun gun by police in recent years as the use of Tasers on youngsters has boomed, a campaign group says.

The figures, obtained under Freedom of Information by Children's Rights Alliance for England (CRAE), show Lewisham's total is the joint second highest in the capital.

And the borough is one of four - along with Croydon, Southwark and Lambeth - which account for 40 per cent of the cases, which campaigners say shows youngsters' rights are a "postcode lottery".            

Group director Paola Uccellari said: "Children living in the same city are experiencing vastly different treatment, depending on where they happen to grow up.

"This is not always linked to obvious explanations such as high child poverty or crime rates."

The figures also show that, London-wide, under-18s were targeted just nine times in 2008 but 53 times in 2012 - a six-fold increase.

In 2008, the UN Committee on the Rights of the Child expressed concern at the authorisation of Taser guns for police officers in England and Wales, and specifically on their authorisation for use on children.

It called for Tasers to be classified as weapons - and to be subject to rules and restrictions on their use.

Mr Uccellari added: "Our report shows too many children in London are falling through the human rights safety net.

"By putting children’s rights and interests at the heart of their work, local authorities can ensure better outcomes for children across the board."

The report also identified a 66 per cent fall in the use of stop and search powers against London children between 2009 and 2013, but, again, showed differences across the boroughs.

Use of the technique in Greenwich and Lewisham was lower last year compared to boroughs like Southwark.

A spokeswoman for the Met Police said: "The increased use of Taser on under 18-year-olds is in line with the general increase in the use of Taser across the board which is as a direct result of the fact that over the past year taser-trained officers are now present on all 32 boroughs.

"It is important to note that in the majority of cases the presence of a Taser (drawn, aimed, red dot, arced) is sufficient in bringing a violent or potentially violent situation to a swift conclusion.

"All officers authorised to carry Taser are thoroughly trained, and use it in accordance with all the relevant guidelines.

"The situations in which Taser is considered for use, along with existing tactical options, are those involving violence or threats of violence with such severity that officers would need to use force to protect the public, the subject themselves and their colleagues.

"Taser creates space between the subject and police, reducing the need for physical contact and also the risk of unintended or unnecessary injuries to all parties.

"Every use is recorded and monitored."