Italian businessman Massimo Cellino has been disqualified from buying a majority stake in Championship club Leeds.
The Football League in England announced that he has failed the 'owners and directors test'.
Cellino was recently found guilty by a court in Sardinia of the non-payment of import duties.
The owner of Serie A side Cagliari was convicted of a failure to pay tax on a yacht.
This breaks the Football League's test of whether an owner has been convicted of an act considered to be dishonest.
After its ruling, the Football League released a statement, addressing the issue:
At its meeting on Sunday evening, the board of the Football League considered the eligibility of Massimo Cellino under its owners' and directors' test.
The board considered detailed legal advice with regard to the application of its regulations within the context of a decision made under Italian law.
Mr Cellino was recently found guilty beyond reasonable doubt by a court in Sardinia of an offence under Italian tax legislation relating to the non-payment of import duties on a boat. This resulted in a fine of 600,000 euros, an order for the payment of trial costs and the confiscation of the boat in question.
Having fully considered the matter, the board agreed unanimously that the decision of the Italian court does constitute a disqualifying condition under its owners' and directors' test.
The relevant disqualifying condition being that Massimo Cellino has been convicted of an offence involving acts that would reasonably be considered to be dishonest.
In line with Football League regulations, Massimo Cellino is entitled to appeal against the board's decision within 14 days. In such circumstances, the League would seek to expedite the process to deliver certainty to all parties in the shortest possible timeframe.