During the past three years, 65 municipalities around the country have procured lectures from Riksorganisationen för ett drogfritt Sverige, which calls itself I Say No to Drugs in English.
The organisation has told school pupils that not only narcotics, but also drugs such as paracetamol and anti-depressants, are stored in the body's fat cells and may enter the blood stream decades after being consumed.
"It's simply not true. The least that can be expected of serious public health work is that the knowledge that is spread is based on evidence," said Cecilia Renman, who chairs the Swedish School Doctors' Association.
"It's shows a lack of judgement by the municipalities when they employ these lecturers," Renman added.
Åsa Graaf, the chairman of I Say No to Drugs, told news agency TT that the information provided has been corrected.
"Fat-soluble drugs can remain in the body and re-intoxication may occur. Research has shown this. But we have corrected the statement that it can occur after several decades. Nor should we speak about paracetamol and other medical products in the future," Graaf said.
Svenska Dagbladet also reported that despite describing itself as a politically and religiously independent association, several of I Say No to Drugs' employees are Scientologists and base their lectures on Scientological methods.
Åsa Graaf denied that the association is dominated by one faith.
"If the religious beliefs of certain individuals can be seen as a connection, then there is one. But we are one hell of a mixture of people," Graaf said.