In an ethics complaint filed against Kirk Caldwell on Friday, challenger Charles Djou claims the mayor is understating his income from Territorial Savings Bank.
Djou said bank records and reports show the mayor got about $2 million in Territorial stock as a bank board member but reported just half of that on official ethics disclosures.
Djou also says the bank hired Caldwell for his community connections, not his legal expertise.
"This is nothing more than paying off the mayor for his political connections," he said. "That is wrong."
In a statement, the mayor called the complaint "frivolous."
His campaign says Djou is mistaking "options to buy stock" for actual stock and that Caldwell doesn't own the shares at all. The campaign says Djou knows that and that the complaint will be thrown out after the election.