The social media app is being used by dealers across Teesside to advertise substances and arrange drug deals.

The BBC's Inside Out used a 14-year-old decoy, whose profile clearly showed he was a schoolboy, who was able to buy two grams of MDMA.

They were picked up by an undercover reporter. The deal was arranged in seconds and was delivered in minutes.

Snapchat is a social media app that allows people to post photos and video, which then disappear once they have been read.

Our reporter discovered a number of Snapchat accounts posting regular videos showing large amounts of cocaine, MDMA, ketamine and cannabis.

Dealers post videos that promote the drugs they have for sale, as well as sending daily offers and advertisements via private messaging.

One dealer claimed to be giving away an ounce (28g) of MDMA in a raffle users could only enter if they promoted the dealer's account to two of their friends. This "prize" could have had a street value of up to £1,400.

Users in Middlesbrough can buy drugs for as little as £10.

Our reporter used Snapchat to buy cocaine in Dock Street in Middlesbrough and the MDMA was handed over in Linthorpe Road in the town during a two-week investigation.

The reporter then used a Home Office-approved kit to check the drugs were real.

Harry Shapiro, a drugs adviser, said: "There's no way you can varnish the truth about this, the worst that can happen to young people who consume a two gram bag of MDMA is they run the risk of dying. It's as simple as that."

Carson Price, from Hengoed in south Wales, died last April after taking an ecstasy pill he bought on Snapchat.

His mother Tatum Price said: "I blame Snapchat. If they were unable to advertise on Snapchat Carson wouldn't have been able to get hold of those drugs.

"I shouldn't even know where my local cemetery is, let alone go and visit my 13-year-old child."

The National Crime Agency said the issue was "alarming" and acknowledged it was a "growing threat".

Esther Rantzen, founder of Childline, said the findings were "shocking".

"I would say to Snapchat it's quite clear that you created this service to provide entertainment and fun.

"You don't want to kill children but if it's misused that will be the effect, you've got to do something to protect children, to protect young people and stop this murderous trade," she said.

Snapchat, which claims to reach more than 60% of 13-34 year-olds in the UK, said it worked with the relevant authorities to ensure it was a positive and safe environment.

It added it encouraged users to report illegal activity on the platform.