The Minnesota dentist at the centre of an uproar for killing a beloved lion, Cecil, in Zimbabwe has returned to work to shouts of "murderer" and "leave town" from a half-dozen protesters as police stand guard.

Walter Palmer, 55, arrived at about 7 a.m. local time to the Bloomington, Minn, dental practice that he shut down in late July amid a firestorm of protests after he was publicly identified as the hunter who killed the rare black-maned lion.

Palmer entered his Bloomington clinic without a word to media gathered outside. He parked nearby and walked to his clinic from the street. A staff member met him on the sidewalk, grabbed his arm and parted a throng of media to rush him to the front door.

Zimbabwe Lion Killed

Cecil, a rare black-maned lion, was a major tourist attraction in Hwange National Park and had been fitted with a GPS collar as part of Oxford University lion research. (Andy Loveridge/Wildlife Conservation Research Unit/Associated Press)

Employees also have been escorting patients from their vehicles into Palmer's clinic, which opened a few weeks earlier without him. Bloomington police were on hand trying to minimize traffic congestion and in case problems arose.

In an interview Sunday with The Associated Press and the Minneapolis Star Tribune, Palmer reiterated that his hunt was legal.

Zimbabwe may have cooled on seeking Palmer's extradition

Zimbabwean authorities earlier said they would seek to extradite Palmer on charges tied to participating in a hunt deemed illegal. But they seem to have cooled off on pursuing the case amid fears that extraditing the American bow hunter could hurt the country's hunting business.

It has been a month since Environment, Water and Climate Minister Oppah Muchinguri announced that the police would process paperwork to extradite Palmer for participating in a hunt that authorities there said was illegal.

The National Prosecuting Authority, which is responsible for processing extradition requests, said Palmer was not on its files because the police had yet to process a docket for him.

Theo Bronkhorst, a Zimbabwean professional hunter who helped Palmer, has been charged with "failure to prevent an illegal hunt." Honest Ndlovu, whose property is near Hwange National Park, faces a charge of allowing the lion hunt to occur on his farm without proper authority. The hunters allegedly lured Cecil out of Hwange with an animal carcass. 

Cecil was a fixture in the park and had been fitted with a GPS collar as part of Oxford University lion research.

Pursuing Palmer without a concrete case could rattle potential big-paying customers from the United States, which along with Germany and Spain is where most of the country's hunting clients come from.

According to a Zimbabwean safari association, hunting supports about 800,000 rural Zimbabwean families.

With files from Reuters