HARARE • A wealthy American dentist who used a bow and arrow to shoot Zimbabwe's beloved Cecil the lion is facing fierce criticism, amid allegations that it took 40 hours for the animal to die.

The lion, a popular attraction among international visitors to the Hwange National Park, was lured outside the park's boundaries by bait and killed earlier this month.

Zimbabwean officials said Dr Walter J. Palmer, an American hunter known for killing big game, fired at Cecil with a cross bow. That shot was not enough to kill the lion and Cecil was tracked for nearly two days before one of the members of the hunting party killed him with a gun. He was beheaded, according to conservation officials, and his corpse left to rot in the sun.

Even in a country which relies on big game hunting for a share of its income from tourism, the death of Cecil has stirred up controversy. He was well known to visitors to the park in western Zimbabwe for his jet black mane .

Wildlife officials on Tuesday accused Dr Palmer, a Minnesota dentist, of killing Cecil without a permit after paying US$50,000 (S$68,000) to two people who lured the beast outside the sanctuary to its death. He is now being sought on poaching charges.

The details of the lion's death have outraged conservationists troubled by wealthy big game hunters who pay tens of thousands of dollars for licences to kill protected animals for trophies and sport. Thousands of people have signed a petition, intended for Zimbabwe President Robert Mugabe, demanding justice for Cecil, and angry animal rights supporters have gone online to express their outrage.

Dr Palmer, known for his skills in hunting without firearms, in 2008 was fined US$2,938 and put on probation after pleading guilty to lying to officials about killing a black bear outside a hunting zone in Wisconsin. Once Dr Palmer was named as the hunter who killed Cecil, his office in Minneapolis closed abruptly, his dentistry website was taken offline, and social media users went on the offensive.

"Murderer," wrote one.

In a statement, Dr Palmer defended his actions, saying he believed what he had done was legal.

"I had no idea that the lion I took was a known, local favourite, was collared and part of a study until the end of the hunt," he said.

"I relied on the expertise of my local professional guides to ensure a legal hunt."

He said he had not yet been contacted by Zimbabwean authorities.

NEW YORK TIMES, REUTERS