The reality TV personality and bail bondsman - born Duane Chapman - was declined permission to enter the country as a result of a previous conviction. He had been tipped to take part in the latest series of Celebrity Big Brother.
"It's something that follows you the rest of your life, no matter who you become or who you are," Chapman is quoted as telling The AP. "I'm not proud of it."
Chapman was sentenced to five years in prison after being found guilty of murder in the 1976, but was granted parole 18 months into his sentence.
The 59-year-old explained that he had been sitting outside a house in Pampa, Texas while a friend went to purchase marijuana. Chapman's friend became involved in an argument with the marijuana dealer and shot him dead.
As a result of Texan law at the time, Chapman and a number of others who were present at the scene were convicted.
Former Pampa police officer Charles Love, who served on the case in the 1970s, submitted a statement in support of Chapman's application for a Temporary Worker Visa, describing him as a "model inmate" and saying that his role in the crime was minor.
"He was just at the wrong place at the wrong time with the wrong people," Love - now a deputy sheriff in Roberts County, Texas - said on Tuesday (August 14). "I know they have rules, but that's 35 years ago. I think he deserves a chance."
The Home Office said in a statement that it does not comment on individual cases and that all visa applications are subject "to the same rigorous checks" by the UK Border Agency.
Chapman is reportedly appealing the decision.
Celebrity Big Brother starts tonight (Wednesday, August 15) at 9pm on Channel 5.
Photo gallery - Celebrity Big Brother, summer 2012 - rumoured housemates: