The former Liverpool and Marseille striker told l'Equipe he was "one million percent" confident he will be exonerated of any wrongdoing.
"If I'd done something stupid I'd own up to it," said Cissé, 36, who currently plays for Yverdon in the Swiss third division. "Apart from informing Mathieu and telling him to be careful, I can't see what I can be reproached for. Those who deserve it will be convicted, but I'm one million percent confident."
The interminable sex tape affair broke in 2015 after Valbuena, who now plays for Fenerbahce in Turkey, was the victim of an attempt to blackmail him over the intimate tape.
His fellow France international Karim Benzema of Real Madrid and Cissé were amongst a number of people accused of involvement in the blackmail attempt.
Benzema and Cissé are both under investigation for "complicity to and attempted blackmail".