A number of players, including former Grifone stars Domenico Criscito and Omar Milanetto, have been implemented in the case, but the 64-year-old businessman has quashed rumours that the Argentine is guilty of fixing the Derby della Lanterna against Sampdoria back in 2011.
Palacio has since been sold to Inter for €10 million, but Preziosi still felt it important to defend his former star.
"Only those who do not know Palacio think that he may have conspired to lose the derby," he told Gazzetta dello Sport. "I am so sure of his innocence that if he is suspended, I am willing to bring him back to Genoa and return the €10m that was paid by Inter.
"It is just bar talk, spoken by people who have no credibility. We cannot smear people like this, we need serious evidence.
"Rodrigo is a clean person, a wonderful guy and a winner. He would not commit a crime like this.
"His agent has called me, saying Rodrigo is in disbelief. He has been crying reading the newspapers and feels unjustly accused. All I can say is to stay calm and everything will be resolved soon."