As "Dog the Bounty Hunter", Duane Chapman has made a name for himself tracking down offenders on his hit US reality TV show, but his own criminal past came back to haunt him when the UK government refused to grant him a visa.

Chapman, whose show has run for eight seasons in the States, was due to appear on Channel 5's new series of Celebrity Big Brother from Wednesday but the UK Border Agency denied him entry because of his involvement in the 1976 murder of Jerry Oliver in Pampa, Texas.

Oliver was shot dead by one of Chapman's friends when they went to buy marijuana from him. Chapman was outside waiting in a car when Oliver was killed inside his house during a struggle. Nevertheless, he was convicted of first-degree murder and served one and a half years of a five-year sentence.

Chapman said he was not seeking to minimise his involvement – "I should not have been there, that's that" – but insisted he had turned his life around. His show, screened on Sky2 and Pick TV in the UK, features him praying with his family for safety and for a successful mission "in Jesus's name" before going to work on criminals, who frequently repent in his presence.

A sworn letter provided by Charles Love, a Pampa police officer at the time of the murder, provided as supporting evidence for Chapman's visa application, described the bounty hunter's role as "minor".

"I'd like to see your country and I have a lot of fans there and I'd like to meet them," Chapman told the Guardian from Hawaii. "I have always wanted to come here." He was bound by confidentiality from confirming his scheduled appearance in the Celebrity Big Brother House but expressed hope the "red tape" could be overcome.

However, his wife, Beth, who is also his business partner and co-star, was more forthright. "It's just incredible that something that he did 33 years ago is just haunting him," she said. "It prevents him making a living. Our society is so unforgiving it seems, no matter how many good things we do."

She pointed to her husband's work with the Make-A-Wish Foundation. He also has a letter supporting his visa application from a charity called RG1, run by film-makers, which supports young people to lead a life away from crime and wants Chapman to take part in its youth initiative scheme. Additionally, more than 3,500 fans have signed a petition calling for him to be allowed into the UK.

The refusal letter from the UK Border Agency says: "Records show that you were convicted of one offence which carried a sentence of five years. According to those records, that conviction is not spent." It also says the purpose of his visit is not "of a sufficiently compelling nature" to exercise discretionary powers to let him in.

Other US stars have been allowed into the UK despite convictions, including the boxer Mike Tyson, who was granted entry in 2000 at the discretion of then-home secretary Jack Straw, despite his conviction for rape.

Chapman's official website says he is considered "the greatest bounty hunter in the world" and he has made more than 6,000 captures in his 27-year career.

His TV show was recently axed in the US after eight seasons.