"A rumour then began circulating that FIA president Jean Todt had contacted Vettel to warn him about bad language," the Telegraph's new F1 correspondent, Daniel Johnson, revealed on Monday.
Johnson added that the rumour has been "strenuously denied" by the FIA.
"No one's spoken to me about it over the weekend," Red Bull team boss Horner told the BBC. "He should be applauded for saying what he thinks."
Todt had warned drivers about bad language back in 2012, but Horner insisted Red Bull allows its drivers "freedom of expression".