KELOWNA, B.C. - An elementary school student in British Columbia has recovered and returned to class after accidentally overdosing on a powerful drug.

The Central Okanagan school district says the eight-year-old swallowed the drug after finding it on the floor of his classroom in Kelowna last week.

The district says tests of the pinkish, powdery sample obtained by the RCMP indicate it was an illicit form of benzodiazepine, a class of drug commonly prescribed for anxiety, insomnia, muscle spasms and other ailments.

Police have not determined how or why the drug was left in the classroom and an investigation continues.

A news release issued last week by Central Okanagan Superintendent of Schools Kevin Kaardal said staff thoroughly cleaned the classroom and it was inspected by the district's health and safety officials.

The school principal also spoke to the class Monday to help the youngsters understand what happened and remind them about the dangers of handling or eating unknown substances.