Police have been interviewing three NSW primary school students who swallowed pills believed to be the illegal drug ecstasy.
The children - a girl aged 11 and two 10-year-old boys - each took one tablet on Monday during their lunchbreak at Windang Public School, south of Wollongong.
The trio became unwell after eating the tablets, which they thought were strawberry lollies, and received emergency treatment.
Chief Inspector Danny Sharkey, of Lake Illawarra police, said detectives had started their investigation into how the pills had come into the children's possession.
"At this stage the investigation is ongoing, some of the children have been spoken to," Insp Sharkey said.
The legal requirement to involve the Department of Community Services, because of the children's ages, would draw out the process, he said.
Police found several tablets at the school and believe they were from the same batch as those taken by the three year five students.
"There was a presumptive test conducted and as a result of that they (the tablets) were forwarded on for further analysis," Insp Sharkey said.
The tests were being treated as a priority but could still take up to two months, he said.
Insp Sharkey said he could not speculate on the likelihood that any charges would be laid, but indicated the issue of a caution might be the outcome of the investigation.
The NSW Department of Education and Training said it was up to the three students' parents to decide when they would return to school.