Harvard is being sued for sexual discrimination over its attempts to clamp down down on single gender social clubs.

A group of fraternities and sororities accused the elite university of violating their civil rights.

This academic year Harvard began enforcing a policy aimed at stamping out single-sex organisations.

It had stopped formally recognising them in 1984, but they continued operating off campus, and as informal clubs.

The university's latest crackdown meant students who joined such clubs could not serve as captains of sports teams, or as leaders of officially recognised student groups.

Those students also could not receive endorsement letters from college deans for prestigious postgraduate programmes, including becoming Rhodes scholars.