Mr Repiquet described the inquiry as "suspicion abusively cast on Christine Lagarde by a handful of opposition members of parliament for political ends".
Even if two operators are using the same script, she says, some callers may respond differently (or even abusively) depending on the operator's gender or accent.
The American, son of co-owner Tom Hicks, became embroiled in controversy when it emerged he had responded abusively when one supporter contacted him directly about the state of the Premier League club and their finances.