A foreign hunter bribed a ranger at Hwange National Park in Zimbabwe to kill Cecil the lion, the Zimbabwe Conservation Taskforce alleges.
Cecil, 13, had a distinctive black mane and was a much-loved feature of the park.
The animal was shot by a bow and arrow and then stalked for more than 40 hours by a hunter who then killed it with a rifle. The hunter, reported to be a foreign tourist, allegedly beheaded the animal and skinned it afterward.
The head of the Zimbabwe Conservation Task Force, Johnny Rodrigues, said the killing took place on July 6.
A park ranger has now been accused of accepting more than $55,000 in bribes for helping to lure the animal out of the park.
This allegation has not yet been confirmed.
The hunter was reportedly questioned and released. His nationality is unknown, with some early reports stating he was Spanish.
The operator of the safari park has reportedly been arrested and a hearing date scheduled for August 6.