Former world heavyweight champion Mike Tyson has been forced to scrap appearances in London after discovering he is banned from entering the UK.
Tyson, 47, was due in London this week as part of a promotional tour for his new autobiography 'Undisputed Truth', which included a photocall with journalists and a book signing.
However, his publishers said recent changes to UK immigration laws meant he was unable to travel to the country because of his conviction for rape and he has been re-routed to Paris instead.
Tweets posted on Tyson's official Twitter account as recently as Friday suggest the boxer was unaware he would be hit by the changes.
He wrote: "So, UK fans, who is brave enough to get in the ring and ask me a question?"
And then in subsequent tweets added: "Tweet me a question. The five best get to step in the ring and ask me it in person."
A spokesman for HarperCollins, his publishers, said: "There was a change in the UK immigration law in December 2012 of which we were unaware.
"For this reason Mike had to change location to Paris to salvage his press obligations for the UK."
Tyson is currently booked in for a British tour for his one-man Broadway show, directed by Spike Lee, which is booked for eight nights in March next year in London, Glasgow and Manchester.
He was convicted in 1992 for the rape of a teenage beauty queen, and served three years of a six-year sentence. He also has convictions for assault, cocaine possession and driving under the influence.
Under the new immigration rules, any person who has been sentenced to more than four years in prison is barred from entering the country.
The explosive boxer was the youngest man ever to become heavyweight champion of the world after he beat Trevor Berbick in 1986 when he was just 20.
But throughout his career he also courted controversy. He bit opponent Evander Holyfield's ear, went bankrupt, lost his four-year-old daughter in a tragic domestic accident, and was jailed.
A Home Office spokeswoman said: "We would not comment on the details of an individual case.
"We reserve the right to refuse entry to the UK to anyone who is convicted of serious criminal offences.
"In December 2012 we toughened up the rules on entering the UK, replacing the previous discretionary approach with a clearer, stronger framework including mandatory refusals based on the length of, and time since, sentence."