More than 40 university chiefs are reported to have written to the Education Secretary calling for a ban on so-called "essay mills".

The vice-chancellors have called for companies who offer essay-writing services to be made illegal amid fears they are undermining the integrity of degree courses.

As many as one in seven recent graduates may have cheated by using "essay mills" during the last four years, according to a recent study.

Students who get caught face punishment by their university, including possible disqualification, although it is not illegal for a company to offer the service.

The BBC reports that the vice-chancellors are calling for those who provide the services, rather than students who use them, to be targeted by new laws.