New York - The WTA says it will look into the dispute between Serena Williams and chair umpire Carlos Ramos.
Williams was penalised a game for calling the chair umpire a thief during an extended argument at the US Open women's final.
Williams clashed with Ramos, demanding an apology after he initially issued a warning for a code violation in the second set's second game for receiving coaching, which is not allowed during Grand Slam matches.
"There are matters that need to be looked into that took place during the match," the WTA said in a statement.
The WTA said Williams and US Open champion Naomi Osaka both have "great integrity."
Osaka become the first Grand Slam champion from Japan, beating Williams 6-2, 6-4 on Saturday.