The email reads: "There is a very scary thing going on in the schools right now that we all need to be aware of."

"There is a type of crystal meth going around that looks like strawberry pop rocks, the candy that sizzles and pops in your mouth."

"It also smells like strawberry and it is being handed out to kids in school yards."

"They are calling it strawberry meth or strawberry quick."

"Kids are ingesting this, thinking that it is candy and being rushed off to the hospital in dire condition."

"It also comes in chocolate, peanut butter, cola, cherry, grape and orange."

"Please instruct your children not to accept candy from strangers and even not to accept candy that looks like this from a friend and to take any that they may have to a teacher, principal, etc, immediately."

"Pass this email on to as many people as you can so that we can raise awareness and hopefully prevent any tragedies from occurring."

The alert was forwarded by the policemen to schools in the area, who then held special assemblies to inform pupils.

"Our head of year was talking about how strangers had been handing out sweets in the style of ones that crackle in your mouth that have been laced with drugs," said Freddie Peppiatt, a 13-year-old pupil at Wood Green School in Witney.

"He said it was crystal meth."

"He was saying how there had been two incidents of children who have been taken to John Radcliffe Hospital immediately because they had taken them without knowing what they are."

When it emerged that strawberry meth was in fact an urban myth, the school held another assembly to explain.

"I'm not surprised at all. I had a sense it was urban mythish," said Francoise, mother of Freddie.

"Perhaps the police should check their facts."

"However, they had the best of intentions."

"There is still a valuable lesson to children about not accepting sweets from strangers."

The policeman in question will not be disciplined, as he was acting in good faith.

"We would like to apologise for any unnecessary concern that we may have caused to schools or parents by sending the warning out about a drug that proved a hoax," said Thames Valley Chief Inspector Dennis Evernden.

"The officer should have double checked before taking this action, which he did take with the best intentions."

"We will be making sure that this does not happen again."