A French junior school teacher has been suspended after he read passages from the Bible to students, aged between nine and 11.

The decision to suspend the teacher was made by his headteacher after an anonymous letter was sent to the school authorities denouncing his lessons. Although students in France are permitted to learn about religions and religious texts, any form of proselytising is strictly prohibited under laws designed to uphold France’s adherence to secularism.

The local authorities have made it clear that his suspension is not intended as a punishment but merely a measure to allow an investigation into the incident to take place, France Bleu radio has reported.

Nonetheless, local mayor François Broggi denounced the “”disproportionate measure”, saying the teacher was “very much appreciated” by his pupils and their parents.

Teaching unions have been less willing to slam the move. Raphael Tripon, co-secretary of the local branch of the Snuipp-FSU, admitted that, if proven, the charge of teaching the Bible would be enough to warrant the sacking of the teacher. But he added that it would be an exceptionally severe measure, likely intended to serve as an example.

A decision will be made on whether the teacher will be reinstated in March.

France takes its principle of laïcité, or secularism, very seriously. In 2013, the government unveiled a “secularism charter” designed to keep all religion out of schools. Announcing the measures, Education Minister Vincent Peillon said they were designed to promote “absolute respect for freedom of conscience”.

Under the new rules, a charter of 15 articles was mandated to be displayed in a prominent position in every school, to remind teachers and pupils alike of France’s Republican principles.

Article 11 states: “Staff have a duty of strict neutrality. They must not show their political or religious convictions in the exercise of their duties.”