Zimbabwe has called for Cecil the lion killer Walter Palmer to be extradited from the US over the "illegal" killing.
Officials allege Palmer, a 55-year-old dentist from Minnesota, broke the law by financing an illegal hunt.
Palmer claims he thought it was organised above board and did not know Cecil was the country's oldest and most famous lion.
Environment minister Oppah Muchinguri said she understood the Prosecutor-General had already started extradition proceedings against the "foreign poacher".
American philanthropists have pledged to match new donations up to $100,000 to the research team who had been tracking Cecil since 2008.
Dozens of protesters gathered outside the practice of a suburban Minneapolis dentist who killed a protected lion in Zimbabwe.
A host of celebrities have taken to social media to speak out on the killing of well-known lion Cecil in Zimbabwe by a US dentist.