A group of students have been sent back to the UK after Indian officials said they had the wrong kind of visa to visit a charity they were supporting.
The 16 students and three staff were refused entry at Chennai Airport by immigration staff even though the school had made three previous visits.
Poynton High School head teacher David Waugh said the school and local community was "shocked and saddened".
Nobody from the Indian High Commission was available for comment.
The school said airport officials claimed the group had no rights to enter the country on their visa because they were going to be undertaking work with a non-governmental organisation.
The group had to return home with the toys and other items it was taking to the children in India.
Mr Waugh said: "They were going to play with the children they have helped and paint a mural.
"The staff and students are in a state of tired shock having travelled for 48 hours as a round trip."
Mr Waugh said he had contacted the Indian High Commission to complain but it had just referred him to its website.
He said the Foreign Office is now pursuing the issue with the Indian Government.
The school has raised more than £27,000 since 2005 for a small charity based in Macclesfield called India Direct which has supported building and running two children's homes in India.
India Direct was set up after the Boxing Day tsunami in 2004.
The charity said: "Our hearts go out to this great team of staff and students, who have already made a real difference, and who must be so disappointed."