The father of a five-year-old boy who brought drugs home from school said the incident could have happened anywhere.
The child at the centre of the case attends Mossgiel Primary School
The youngster, a pupil in Dundee, brought the suspicious substance home last week which police tests have now confirmed as amphetamine.
The boy's father, Allan Petrie, put the incident down to what he described as the country's "drug culture".
Meanwhile, police inquiries are continuing to discover how the drug came into the boy's possession.
Mr Petrie, 35, of Dundee's Lanlathen area, who found the drugs in his son's coat pocket, said it had been a traumatic time for the primary one pupil.
The single father-of-four praised the school for its "excellent" teachers, adding: "This could have happened at any school.
"It's society in general and it's the drug culture in this country. Something has to be done about this."
Mr Petrie, a voluntary worker, said: "When it gets to the stage that a five-year-old boy is able to get this drug in a place of safety, that really concerns me."
His son, who apparently found the amphetamine, commonly known as speed, in a school work tray, did not ingest any of the substance.
Mr Petrie said he hoped the culprit would be caught, adding: "If someone else has brought drugs into the school then that child is in serous danger."
Superintendent Aaron Duncan, of Tayside Police, said officers were speaking to teachers at the school as part of the inquiry.
Allan Petrie said he hoped the culprit would be caught
"Obviously it is of great concern to us that a child in a primary school is found to be in possession of drugs," he said.
Parents of other children have critised Mossgiel Primary and city education officials for failing to keep them informed about the case.
Local residents whose children attend Mossgiel Primary criticised the handling of the discovery.
One parent said she first heard about the incident on the news.
She said: "It's absolutely disgusting. My son is in that classroom."
A man whose grandchild attends the school also claimed parents were not properly informed.
He said: "It's scandalous. There has to be a big inquiry about this.
"That kid could have taken it himself or passed it onto other kids. I don't think they really appreciate how serious it is."
A Dundee City Council spokesman said the local authority and the school were co-operating with the Tayside Police investigation into the matter.
"We are assisting police as they work to establish if any substance was found in the school," he said.