Sky Sports pundit Matthew Macklin was prevented from travelling to the US this week because of his previous links to mob boss Daniel Kinahan.
Macklin was due to travel to Las Vegas to work for the broadcaster, covering the super-featherweight title fight between Shakur Stevenson and Oscar Valdez.
But on instruction from US authorities, Macklin was stopped from boarding a flight in London.
Read More: Mafia expert warns Kinahan cartel will go on - even if mob boss Daniel is arrested or killed
It is understood that Macklin is one of a number of people who were turned away because of their previous associations with drug baron Kinahan.
Dubliner Kinahan had a $5million bounty put on his head and was hit with sanctions by the US Government, along with his father Christy Snr and brother Christy Jnr, while the UAE freezed the mob's assets earlier this month.
Macklin, 39, has no involvement in crime but the former professional puncher had previously described Kinahan as having been his "best friend."
While he was still fighting, Macklin and Kinahan founded MGM in Marbella.
It was the boxing firm's event at the Regency Hotel in February 2016 where a Hutch gang hit team stormed in as they targeted Kinahan.
The now 44-year-old managed to escape but his senior associate David Byrne was blasted to death.
MGM later rebranded as MTK Global before claiming Kinahan had stepped away from the firm in 2017.
However, the company is now folding after major figures in the sport refuse to do business with it on foot of US sanctions because of its links to Kinahan.
Sky Sports has stood by Macklin but today refused to comment specifically on him being prevented from travelling to the US.
The broadcaster says he has had no dealings with Kinahan since 2017.
A spokesman said: "Matthew Macklin relinquished his interest in MTK in 2017, and has had no commercial dealings with Daniel Kinahan since.
"Matthew Macklin is not a named individual in the US sanctions, nor does he have any interest in, or prior dealings with, the named companies.
"However, he will of course be fully compliant with any responsibilities which may arise from the sanctions."
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