Florida's Republican Party accused Gov. Charlie Crist and two former party bosses on Saturday of misspending "hundreds of thousands" of dollars — but offered no proof, newspapers in the state reported.
Greer is facing fraud and money laundering charges related to party spending.
Thrasher didn't provide a firm number but said Greer could owe "hundreds of thousands" of dollars and that Crist was in "that ballpark," the Orlando Sentinel said.
Thrasher also pointed to more than $300,000 in consulting fees paid to a Crist ally, saying he didn't see the value of the deal, the Herald reported.
But Greer's attorney, Damon Chase, noted that Thrasher and other party leaders had approved spending under Greer as part of a severance deal to get him out of office, the Herald said.
Crist had been the GOP's chosen candidate in the race until Marco Rubio, a tea party-backed candidate, outdistanced Crist in the polls. Crist left the Republican Party in April to run as an independent. Kendrick Meek won the Democratic primary, although polls show him far behind the other two.
Since Crist's decision to leave the party, he has been a target of attacks by the GOP.
Crist spokesman Danny Kanner said the GOP should "stop playing the same old political games and take a hard look at their own nominee," the Sentinel reported.
The state party refused to release the audit its allegations were based on. Thrasher said the party was considering a lawsuit against Crist, Greer and Johnson.