Vic students caught with drugs at formal

An elite Melbourne girls school will be visited by police after it was revealed several students were caught with drugs at the school formal, Victoria's top cop says.

Three students at Melbourne Girls Grammar were reportedly caught in the toilets at the Year 12 formal on Friday night, one with a significant number of pills.

The school has expelled one student and suspended a further two over the incident.

"All students are aware of our strict policies surrounding illicit substances and agree to abide by our zero tolerance," principal Catherine Mission said on Wednesday.

Chief Commissioner Graham Ashton revealed no formal complaint had been made but police would be visiting the school on Wednesday.

"If there's trafficking we're more than interested because that's where we will be laying criminal charges," Mr Ashton told ABC radio.