A professional hunter is due to stand trial in Zimbabwe today accused of failing to prevent Walter Palmer's unlawful killing of Cecil the lion.

Theo Bronkhorst allegedly lured the 13-year-old lion away from the safety of Hwange National Park with an animal carcass.

Mr Palmer, a dentist from Minnesota, then shot the pride leader with a high-powered bow and arrow.

Wounded, the black-maned lion managed to escape - but was allegedly tracked down and killed 40 hours later.

Bronkhorst and Mr Palmer have denied any wrongdoing, and have claimed they were unaware that Cecil had been collared and protected.

Although Mr Palmer has not been charged with any offence, there have been growing calls for the US tourist to be extradited to Zimbabwe to stand trial.

The White House is currently reviewing a petition which has been signed by more than 140,000 people.

Cecil's death has caused an international outcry. Mr Palmer has been pilloried on social media, and there have been protests at his dental practice.

He has been a trophy hunter for years, and there's no shortage of pictures which show him posing with other big game he has slaughtered.

It has been reported Mr Palmer paid €50,000 to track and kill Cecil on July 1st.

The well-loved and well-known lion was part of a long-term conservation study being overseen by Oxford University, and he was wearing a radio collar when he was shot.

It is claimed hunters removed the collar and left it in a tree.

However, the university's Wildlife Conservation Research Unit (WildCRU) has come under scrutiny after it emerged the group's research into African wildlife is funded by companies that support "sustainable trophy hunting".

Prof David Macdonald, the unit's founder, has insisted there is no conflict of interest between its work and sources of funding.

Animal conservationists now have the multi-million dollar business of big game hunting in their sights, and Cecil's death may well make life a little safer for those he leaves behind.