Tyson Fury and other former MTK boxers and their teams have been booking flights to the US to 'test the waters' to see if they can fly.
The boxers are understood to be so flabbergasted by the sanctions against the Kinahan mafia that they cannot believe they have been caught up in a travel ban.
Fury was refused entry to the US for the first time on Friday after he booked a flight from the UK. In a huge blow to his fighting career, he was informed he would not be granted entry Stateside, as he attempts to distance himself from the mob boss.
Despite posting social media pictures of himself in Miami in recent days, Fury has not entered the US since his former fight fixer Daniel Kinahan was sanctioned by the US Treasury in April.
Fury was informed on Friday evening that he was being denied access to the US.
More than 600 people, including the world heavyweight champion, are on the banned list because of their direct association with drug boss Daniel Kinahan.
The implications of the entry refusal for the boxers is likely to cost them hundreds of millions of dollars and is a clear message of the commitment of US law enforcement to the takedown of the Kinahan Organised Crime Group.
Christy Kinahan Snr and his sons have a $5million bounty on their heads since the stunning announcements of sanctions against them, their associates and businesses linked to them.
Further sanctions are expected to be announced in the near future, intensifying pressure on the organisation which has been in chaos since.
Tyson Fury has been desperate to distance himself from Daniel Kinahan since the announcements were made and he stormed out of an interview when asked about his friendship and business relationship with the mob boss before his fight against Dillian Whyte.
In the aftermath of the bout he announced his retirement from boxing, but his wife Paris has suggested that he hasn't hung up his gloves for good.
The news this weekend that Fury is on the banned list will be devastating to any future career plans to fight in the money-spinning US market.
Previously, lesser-known associates of Kinahan have been refused entry to the US, including his one-time best friend and the founder of the boxing giant MTK, which grew out of the MGM gym in Marbella, Matthew Macklin.
Macklin, who has no involvement in crime, continues to work for Sky Sports as a commentator despite his past links to Kinahan and his role as a co-founder of the boxing company that folded within a week of the US sanctions being announced.
Kugan Cassius, a journalist whose independent boxing network was sponsored by MTK at the height of their power in the sport, has also been refused travel.
The sanctions against the Kinahan mob are likely to take months if not more than a year to take full effect as their business interests are thwarted at every level.
Kinahan Snr remains convinced he has a leak within his own organisation and Sean McGovern, wanted for murder before the Irish courts, has become the focus of his attention.
Few within the Kinahan inner circle are close enough to the father and his sons to have the level of intelligence now understood to be in the hands of law enforcement.
While Kinahan Snr initially believed he had a DEA undercover operative in his organisation he is now sure he does not.
The Kinahans are under assault from all angles with their names and faces on Wanted posters in the US and their businesses turned toxic due to the sanctions.
International policing partners are awaiting moves by their colleagues in the United Arab Emirates who have been issued with an arrest warrant for McGovern and the US declarations against the Kinahans.
Daniel Kinahan had laid down significant business and social partnerships in Dubai before he was named by the US treasury.
He had befriended a member of the royal family and employed a number of influential Emiratis in his businesses.
His father, Christy Kinahan Snr, was moonlighting in the country as a respectable aviation broker despite his long history in organised crime and his convictions for heroin trafficking and money laundering.
US officials described the Kinahan group as a trans global weapons and drugs organisation worth a staggering $1 billion.