Kevin Thompson, 14, was believed to have been a victim of the "choking game", police have since said.

“The Delaware State Police can’t comment on the specifics of this case,” Delaware State Police spokesman Gary Fournier said.

“But troopers want to make sure parents warn their kids about any games that have a person tie an object around their neck to the point of passing out to obtain a euphoric high.”

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Fournier confirmed that state police are investigating the teen’s death, but added that the cause and manner of the boy’s passing have not yet been determined.

The Choking or Passing Out Game involves children cutting off the oxygen supply to the brain until they pass out.

There are a number of ways they do this: one involves a child putting their thumb in their mouth and blowing hard, non-stop, until they pass out; another involves hyperventilating - breathing out in a succession of short breaths, depriving their brain of oxygen; in another practice, a child will lean heavily on a classmate's chest to prevent them breathing in; and in the most extreme case, children grab a fellow pupil by the neck, stopping the flow of oxygenated blood from the catoroid artery to the brain.

This deprivation of oxygen to the brain is said to produce a sense of euphoria - but it is, obviously, highly dangerous.

The dangerous craze, which began in America, has now reached school yards in Britain, prompting the head of a leading private girls' school to write to parents voicing her concerns about the so-called games.

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In an email, the concerned head teacher said: "I am writing to you as it has come to my attention that there is a current trend among young people for choking or fainting 'games'.

"Apparently this has been played at parties and also in schools in the area. It is particularly popular among Year 9 students, but younger children sometimes copy older ones.

"I am very worried about this, as what appears to young people to be a harmless 'fun' activity can in fact lead to coma and possibly death.

"We will speak to the girls at school and we would be most grateful if you could reiterate this message at home.

"These games are extremely dangerous. Whilst girls involved in this will be in breach of the school rules, much more serious is the possible risk to life."

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Paediatrician Dr. Michael McKenna has added that the craze 'could have a long-term impact' on kids.

He said: "Any time you're messing with oxygen supply to the brain you are putting yourself at extreme risk.

"Whether that's risk of death or whether that's risk of damage to the brain."

Signs that a child might be trying the choking game are:

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Parents are advised to talk to children about what can happen if they try the activity - and pay attention to what they are viewing on the internet.

Psychiatric social worker Judy Rogg, whose 16-year-old son Erik died playing the game, has said the strategy is to avoid "shock-and-awe" tactics that often make kids just shut parents out.

"Just talk with them while you're driving somewhere or something like that," she said.

"Be honest with them. Be open about it. Just let them know that you care and you don't want anything bad to happen to them."

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