Chris Oswald, of the Disability Rights Commission, said yesterday that he was "shocked" by the case of 10-year-old Oliver McCleary.
He said the youngster had been receiving personal tuition in a store cupboard for the past seven months at Castle Douglas Primary School in Dumfries and Galloway.
The local education authority said he had not been able to use a new £50,000 portable classroom because special safety furniture had yet to be installed.
Mr Oswald said: "This is a shocking situation and on the face of it a breach of the Disability and Discrimination Act 1995.
"The law requires educational authorities to treat disabled children equally and to make reasonable arrangements to enable them to participate fully in education."
Dumfries and Galloway Council said teachers and other staff had been working very hard to accommodate the pupil. A spokesman said there was a delay in equipping the learning centre, but that it is now ready and the council believes this will alleviate the problem.
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