Zimbabwe has called for Walter Palmer, a trophy hunter from Minnesota, to be extradited from the United States for shooting Cecil the lion, whose death triggered worldwide outrage.
Palmer allegedly paid US$50,000 for the hunt earlier this month in which he shot the lion with a powerful bow and arrow close to Hwange national park in the west of Zimbabwe.
Cecil, who had a distinctive black mane, was a popular tourist attraction among visitors to the park and was also wearing a collar as part of a University of Oxford research project.
"We are appealing to the responsible authorities for [Palmer's] extradition to Zimbabwe so that he can be made accountable for his illegal actions," environment minister Oppah Muchinguri said in Harare on Friday (local time).
"Unfortunately it was too late to apprehend the foreign poacher as he had already absconded to his country of origin."
Palmer, who has gone into hiding amid a flood of angry abuse and criticism, has apologised for killing Cecil and said he was misled by professional guide Theo Bronkhorst.
Bronkhorst, who organised the expedition, was granted bail by the Hwange court on Wednesday after being charged with "failing to prevent an illegal hunt".
A court hearing for the landowner accused of allowing the hunt was delayed on Thursday.
The US Fish and Wildlife Service on Thursday said it had opened a probe into the hunt.
The agency tweeted:
But Palmer remained out of the public eye, as crowds left plush toys of lions, tigers and monkeys at his River Bluff Dental practice in Minnesota.
A sign reading "Rot in Hell" was plastered on the office door.
A Minnesota congresswoman joined calls to investigate the dentist, a seasoned hunter with a poaching conviction over the 2008 killing of a black bear in the US.
"To bait and kill a threatened animal, like this African lion, for sport cannot be called hunting, but rather a disgraceful display of callous cruelty," Betty McCollum said on Wednesday.
She urged the US Attorney's Office and the USFWS to "investigate whether US laws were violated related to conspiracy, bribery of foreign officials, and the illegal hunting of a protected species or animal".
Meanwhile, Safari Club International, an international hunting organisation that Palmer belonged to, said it also supported a probe and that it had revoked his membership.