Costa Mesa police arrested a 12-year-old boy Wednesday on suspicion of bringing a drug-laced brownie to TeWinkle Middle School, according to a news release.
Police said the actual substance that caused three students to be hospitalized had not been determined, but they believe it was marijuana or a derivative.
The boy, whose identity was not released because of his age, was booked on suspicion of contributing to the delinquency of a minor, according to the release.
This was the second such incident at a Costa Mesa school in as many months.
On Wednesday, two seventh-graders went to the TeWinkle front office at 12:40 p.m., complaining of stomach problems, Newport-Mesa Unified School District spokeswoman Laura Boss said.
After school administrators believed they had handled the issue, a third seventh-grader came to the office complaining of similar symptoms, she said.
The three students were taken to a hospital for observation, school officials said. The student suspected of bringing the brownie to school was not transported to the hospital, Boss said.
Two other students are being investigated in relation to the incident.
Expulsion and suspension are possibilities for the students who brought and ate the baked good, depending on if they knew it may have contained a drug, Boss said, but it's unclear if the students were aware.
A similar situation occurred at Pomona Elementary School last month when a student brought a brownie containing pot to school and was later arrested.
Police said they were working with the school district to try to determine the source of the TeWinkle brownie, the substance in it, any other students who may be involved and whether this incident is connected to the one at Pomona.
The district sent out a notification to parents about 1:30 p.m. alerting them to the situation.