FETTES College says a teenage girl has been kicked out after an alleged liaison while on a foreign trip.
The pupil, reported to be a sixth former, is claimed to have been caught in bed with another youth during a visit.
An investigation was carried out by senior staff at the £33,000-a-year school.
It was then decided that she should be shown the door with immediate effect.
In a statement, the college confirmed disciplinary action had been taken.
It read: “Fettes College regret to confirm that an 18-year-old girl broke the school rules on an international school trip.
“As a result of her actions she is no longer a pupil at Fettes College.”
No further details were provided about where the trip had taken place.
There was also no information about who the other youth was or how they were involved in the trip itself.
The girl has not been named by the school.
Fettes is regarded as one of the top schools in the UK.
It counts ex Prime Minister Tony Blair among its former notable former pupils.