Walter Palmer, the dentist from Minnesota who shot 13-year-old Cecil with a crossbow half a mile outside Hwange National Park, has not been charged.

Two Zimbabweans involved in the hunt - Honest Ndlovu, who owns the land on which the country's much-loved lion was shot, and professional hunter Theo Bronkhorst - were granted bail at Hwange Magistrates' Court. If convicted of poaching they could face 15 years in prison. It is believed that Cecil was lured outside the park during nightfall on July 1.

Sir Roger, the former James Bond actor, echoed the demands from many when he called for Mr Palmer to be punished.

"Hunting is a coward's pastime, and no one has demonstrated that more clearly than Walter Palmer," the actor told The Daily Telegraph.

Mr Palmer's love of hunting is well documented, the 55-year-old having shot chamoix in Spain, an elephant in Africa, a rare sheep in California, and even a polar bear.

His shooting has not been without controversy. Court filings obtained by The Daily Telegraph show that, in September 2006, Mr Palmer and friends tracked and killed a black bear in Wisconsin. He then "knowingly made false statements" about where the bear was killed, "and falsely stated that he thought the bear had been killed legally."

Earlier this week Mr Palmer issued a statement explaining his Zimbabwe hunt. "I hired several professional guides and they secured all proper permits. To my knowledge, everything about this trip was legal and properly handled and conducted." he said.

But his words rang hollow to Sir Roger. "Cleary he's gunning his way through the animal kingdom, and who among us feels that we live in a civilised society while he's on the loose?" he said.

"He must be stopped and brought to justice. In a world with boundless opportunities for amusement, it's detestable that anyone would choose to get thrills from killing others who ask for nothing from life but the chance to remain alive."

A petition calling for Mr Palmer to be extradited had last night reached 30,000 signatures. The dentist said he would assist the authorities, but had not been contacted by either Zimbabwean or American police. Legal experts said there was no chance of his extradition, despite a treaty being in place.

"For an offence to be extraditable, there must be 'dual criminality' - that is, the conduct alleged must be a crime in both countries," said Professor Fred Morrison from the University of Minnesota.

"In addition, it must be punishable by a year or more in jail in both countries. While poaching is a serious crime in Africa, it is a less serious issue in the US."

Professor Morrison added that there was also a "practical constraint".

"Extradition is cumbersome and expensive for the extraditing state. It involves a diplomatic note to the US government, a reference to the US Justice Department, a hearing before a federal district judge in the US, and then approval of the extradition by the Secretary of State.

"Even then, Zimbabwe would need to send police officials to the US to return him to Zimbabwe."

Supporters of Mr Palmer argued that the fee he paid to shoot in Zimbabwe would assist conservation of endangered species.

Lions are not endangered, and can be shot legally in Zimbabwe - although not in the national park. Hwange currently has a population of around 500. "I personally wouldn't want to kill a lion, but don't have a problem with hunting those that form part of a sustainable population," said Emelie Mararv, who for the past eight years has run a hunting concession in the Central African Republic.

"Hunters are some of the most passionate conservationists I know. And attacking the dentist is missing the point: it was the professional hunter who should have known better."

Yet last night an angry crowd gathered outside Mr Palmer's surgery in the town of Eden Prairie. Police maintained a discreet presence. One supporter of the beleaguered hunter drove past in a sport utility vehicle. Rolling down his window he shouted: "It was a legal hunt."

He drew an obscene gesture from one woman, while a second yelled: "He's a killer, I hope he loses his business."

A toy animal shrine at the entrance to the surgery included five lions, two bears, two moose, one leopard, a tiger and two chimps. Mourners for Cecil had also strewn three red roses.

Lori Peterson, 52, who was clutching a gory bloodstained sign, seethed with anger.

She said: "It is horrible. I just can't comprehend the joy of shooting a beautiful creature. What he has done to add another trophy to his collection is appalling."