Alderley Edge School for Girls is currently working with the Police regarding an alleged incident involving drugs on the school site on Wednesday, 24th February.
Headmistress Nicola Smillie said "Alderley Edge School for Girls has a zero tolerance policy to drugs and alcohol and we contacted the Police regarding an alleged incident involving drugs on the school site yesterday.
"We are unable to comment further. Schools across the country have thorough policies in place for such situations and the school will be working closely with Police and parents on the alleged isolated incident."
A spokesperson for Cheshire Police said "We are aware and are working with the school to establish the circumstances."