During an appearance on the "Graham Norton Show", Liam said he and his older brother used to have quite physical fights, reported People magazine.
"We were very like-minded, very stubborn and would often get into arguments and because I was so much younger and smaller, I had to use weapons to fight," 26-year-old Liam said on the program, joking that their childhood rivalry was a bit vicious, a bit like "The Hunger Games".
"One day when I was about five we had a fight in the kitchen about using the toaster or something, and I picked up a kitchen knife and threw it at his head and the handle hit him in the forehead," Liam said.
Liam and his older brothers Chris, 32, and Luke, 35, grew up in Melbourne. Their family moved to Victoria's Phillip Island when Liam was in high school.