The highest court in Germany has lifted a ban on headscarves popularly called 'hijab' for state school female teachers, stating that it is unconstitutional.

BBC reports that the court ruled a 2004 ban violated religious freedom.

The case was brought forward by two female Muslim teachers who had been forced to wear alternative head dress.

The ban was imposed on the grounds that headscarves could lead to disruption in classrooms and prompt questions about a teacher's neutrality.

But Christian symbols were exempt from the ban.

Reports say on Friday, the court ruled that schools will now need to show "not only an abstract but a sufficiently specific risk" to justify a ban on the earlier grounds.

It also decided that a clause exempting "Christian and Western educational and cultural values or traditions" from the ban was discriminatory.

In a statement, the Federal Constitutional Court said a "blanket ban on religious expression... based on the outward appearance of educators" was incompatible with religious freedoms.

The teachers originally brought the case against a local law in the state of North Rhine-Westphalia.

It was learnt that other states across the country also ban teachers from wearing headscarves, but this ruling strikes out those laws as well.