The US dentist who killed Cecil the lion wanted to hunt a "very large elephant" after shooting the protected animal, the guide who led the trip has claimed.
Theo Bronkhorst faces criminal charges in Zimbabwe for his role in the famed big cat's death, which has sparked a furious public reaction.
Walter Palmer, who allegedly paid 50,000 dollars (£31,900) to track and shoot the animal, has said he was unaware the lion was protected and had relied on his local guide to ensure the hunt was legal.
Cecil was shot dead by American dentist Walter Palmer
Mr Bronkhorst said the expedition "went wrong from the beginning" because they were late setting off and had not intended to hunt on the land where Cecil was shot.
In an interview with the Daily Telegraph, he said he realised Cecil was protected only after the lion's death. He then hid its collar before taking its head and skin for Mr Palmer's "trophy".
He later reported the killing to the Zimbabwe Parks and Wildlife Management Authority.
He said: "I was devastated. I could not have seen the collar at night. We would never shoot a collared animal. I was devastated, and so was the client, we were both upset, and I panicked and took it off and put it in a tree. I should have taken it to Parks, I admit that.
"So we did what had be done. We took the head and skin, as the client had paid for the trophy. I went to Parks and reported what had happened. I wish I had taken the collar.
"We then went back to my place near Hwange. The client asked if we would find him an elephant larger than 63 pounds (the weight of one tusk) which is a very large elephant, but I told him I would not be able to find one so big, so the client left the next day and went to Bulawayo for the night and then flew out midday the following day."
Theo Bronkhorst faces criminal charges in Zimbabwe for his role in the famed big cat's death
Mr Palmer, from Minneapolis, Minnesota, shot the lion with a bow and arrow at around 10pm after it had been lured by bait, Mr Bronkhorst said, adding it was not until 9am the next day that the hunters finally tracked down and killed the animal.
Cecil's skin and head were to be sent to taxidermist before being exported to the US for mounting but he had been advised to hand it in to authorities instead, the guide said.
US wildlife officials have confirmed they are investigating the circumstances of the lion's death.
Mr Bronkhorst could face up to 15 years in prison, according to the Zimbabwe National Parks and Wildlife Authority and the Safari Operators Association.