Lamia Shakkur appeared on France's BFM television to set the record straight after another channel, France 24, broadcast a telephone interview with a woman posing as her who said she was quitting in protest at the "cycle of violence".
"I accuse France 24 of identity fraud," Shakkur said, appearing on BFM on Wednesday in the Syrian embassy in Paris, in front of a Syrian flag and a portrait of its President Bashar al-Assad.
"I will bring a complaint to convict France 24 for these acts of misinformation, which are part of a campaign of false information against Syria since March 2011," she added.
The woman who spoke on France 24 on Tuesday said she had offered her resignation to Assad because "I cannot support the cycle of violence."
"I recognise the legitimacy of the people's demands for more democracy and freedom," she added.
France 24 raised the alert over a suspected hoax hours after broadcasting the comments.
"We do not rule out a manipulation or a provocation," it said in a statement. "If that is the case, we will sue any persons, organisations or official agencies that may be behind it."
More than 1,100 civilians, including dozens of children, have been killed in a security crackdown against anti-government protests that erupted in Syria in March.
Britain and France are to submit a resolution at the United Nations Security Council later Wednesday condemning the "repression" in Syria, British Prime Minister David Cameron said.