Police have refuted "unwarranted" claims made on a Facebook group set up by parents at Broad Oak Sports College, in Bury, Greater Manchester.
Bury Council bosses and school leaders said social media claims that an imposter pretended to be a year 10 pupil at the school are "completely untrue".
Facebook posts alleged the "man" regularly attended lessons at the school dressed in a white shirt, black trousers and trainers.
Greater Manchester Police confirmed on Thursday he is in fact a "vulnerable" 14-year-old boy from Afghanistan who recently immigrated to the country.
Detective Constable Carolyn Morley: "We have been made aware of reports of an older man posing as a student at a school in Bury.
“Detectives have undertaken enquires into this matter and assessments have been carried out by the relevant agencies, and we are confident that no offences have been committed. This young man is a vulnerable child, fleeing persecution in his country of birth, and this speculation is unwarranted and unhelpful."
