Anthony Crapet has been keeping Ciam, a 14-month-old male lion in his garden in the town of Poussan, southern France, for the last seven months and insists he is no danger.
The man, who lives with his two young children, claims the 140 kilogram (300lbs) lion was a gift from a circus manager, which he has hidden in a wire cage in his garden.
But after a terrified neighbour got wind of the beast in the garden next door and alerted police, Crapet faces the likely prospect of having his animal confiscated, French newspaper Midi Libre reported.
In France individuals are forbidden by law from keep wild animals as pets.
At the weekend officers turned up with the intention of taking away the animal, but after a four-hour stand-off, police ended up leaving empty handed.
It didn't help the situation that Crapet threatened to take his own life.
“I don't want them to take Ciam away. When I took him in, he was all skinny, you could see his ribs. I can do what I like with him, I stroke him. He eats, he's happy,” Crapet told Midi Libre newspaper.
“Does he look aggressive to you? Not at all. I play with him. I stroke him. He's mine,” Crapet said.
But while the owner seems pretty confident he can handle the lion, animal experts say it will end in disaster.
Guy Deldem, who is a member of a local veterinary association said: "It's neither a cat nor a dog. It's a wild animal that's not designed to live with a man communally.
The vet recalled a story of another local man who kept a lion at his home back in the 1980s and ended up getting eaten by the wild cat.
"What was bound to happen, happened," he said.
Crapet was warned by Cyril Vaccaro, who is in charge of carnivores at Sigean - a nearby "African reserve" - that Ciam will soon weigh double his current weight and be "awash with with hormones as he reaches sexual maturity."
"He'll be even more aggressive," he said.
On Tuesday police returned and arrested the man and took him into custody. Authorities also took away his lion with the help of animal rights groups.