The General Teaching Council (GTC) said that the comment by Michael Aldersley at a Liverpool school was "unacceptable professional conduct".

The reprimand will lie on his record of registration as a teacher for two years.

Dr Aldersley made the comment to the three 14-year-old pupils during a lesson at Calderstones Community Comprehensive School.

I only took it to have one meaning...and that is a derogatory phrase towards black pupils

Brian Davies headteacher

Dr Aldersley did not turn up for the hearing in Birmingham.

The GTC panel had heard that the three children and their parents complained about the comment made in November 2000.

Dr Aldersley was suspended before a school disciplinary board sacked him for gross misconduct.

Headteacher Brian Davies said Dr Aldersley, who had taught at the school for 10 years, did not dispute the term he used, but claimed it meant a "stupid, idiot, silly person".

Mr Davies added: "I never considered that it would mean silly or foolish children.

"I only took it to have one meaning...and that is a derogatory phrase towards black pupils."