A US dentist who killed a lion in Zimbabwe says he regrets shooting the well-known animal and insists that he thought he was on a legal hunt.
Police in Zimbabwe have arrested two people over the death of Cecil, the country's most famous lion, and say Mr Palmer may also face poaching charges.
But Mr Palmer, from Minnesota, said he relied on professional guides to find a lion and obtain the necessary permits.
He also said he only found out the lion's identity at the end of the hunt.
The American tourist, who is believed to have paid about $50,000 (£32,000) to go on the hunt, is said to have shot the animal with a crossbow and rifle.
It was later skinned and beheaded, according to the Zimbabwe Conservation Task Force (ZCTF), a local charity.
Two Zimbabwean men - a professional hunter and a farm owner - have been charged with poaching offences because the group did not have a hunting permit.
They could face up to 15 years in prison in Zimbabwe if they are found guilty. They are due to appear in court on Wednesday.
'An activity I love'
But Mr Palmer, who is thought to be back in the US, insisted that his guides had secured "all proper permits" for the hunt.
"I relied on the expertise of my local professional guides to ensure a legal hunt," he said in a statement on Tuesday.
He said he had not been contacted by authorities in Zimbabwe or the US but said he "will assist them in any inquiries they may have".
"Again, I deeply regret that my pursuit of an activity I love and practise responsibly and legally resulted in the taking of this lion," he added.
The dental practice run by Mr Palmer was closed on Tuesday and a note was placed on the door referring visitors to a public relations firm, according to local press.
The practice's Facebook page was removed from the site after being besieged by angry comments and the company website was also taken down.
Zimbabwe, like many African countries, is battling to curb illegal hunting and poaching which threatens to make some of its wildlife extinct.
The 13-year-old lion was a major tourist attraction at the country's famous Hwange National Park.
He is believed to have been killed on 1 July but the carcass was not discovered until a few days later.
The ZCTF said the hunters had used bait to lure him outside Hwange National Park during a night-time pursuit.
Mr Palmer is said to have shot Cecil with a crossbow, injuring the animal. The group didn't find the wounded lion until 40 hours later, when he was shot dead with a gun.
The animal had a GPS collar fitted for a research project by UK-based Oxford University that allowed authorities to track its movements. The hunters tried to destroy it, but failed, according to the ZCTF.
On Monday, the head of the ZCTF told the BBC that Cecil "never bothered anybody" and was "one of the most beautiful animals to look at".
The six cubs of Cecil will now be killed by the new male lion in the pride, Johnny Rodrigues added, in order to encourage the lionesses to mate with him.
"That's how it works... it's in the wild. It's nature taking its course," he added.
About a century ago there were around 200,000 lions roaming across Africa but that figure has dropped to less than 30,000 in recent years.
Hunting lions is legal in several countries in southern Africa, including Zimbabwe, but groups must obtain a valid permit from authorities.