A Zimbabwean court has dropped charges against a professional hunter accused of allowing an American dentist to kill Cecil, a lion whose death in 2015 prompted an international outcry.

Theo Bronkhorst was charged with failing to prevent an illegal hunt after leading dentist Walter Palmer to Cecil, a lion that was popular with tourists and was wearing a GPS collar as part of a Oxford University's Wildlife Conservation Research Unit.

Mr Bronkhorst subsequently applied to a court, arguing that the charge was vague and that the circumstances did not constitute a chargeable offence.

His lawyer, Perpetua Dube, said the court upheld the application.

Prosecutors can still pursue the case.

Zimbabwe initially said it would charge Mr Palmer but later dropped that plan.