In December last year, Juventus revealed that they were being investigated by Italian prosecutors.
Then the deal about Cristiano Ronaldo, who returned to Manchester United from Juventus this summer, was pointed out as of particular interest to the investigation.
The club is also said to have been investigated for allegations of fraud in its accounts and for giving investors incorrect information.
At that time, the Italian Football Association also started an investigation into transfers to and from several clubs.
But when the union's legal body tried the issue on Good Friday, all clubs were found innocent of irregularities, the union writes in a statement.
Other clubs whose financial procedures have been investigated are the Serie A club Genoa, as well as Empoli, Pro Vercelli, Parma, Pisa, Chievo, Novara and Pescara, in lower divisions.