A German magazine this week revealed that, in Canada, the FIA asked the reigning champions to remove a hand-adjustable damper system from the RB8.
The rules state that the adjustments can only be made with a special tool, thus ensuring a team cannot secretly make performance-enhancing changes during the strict 'parc ferme' period between qualifying and the race.
It is just the latest technical controversy involving Red Bull, hot on the heels of the 'hole in the floor' saga earlier this year, a wheel hub issue, and most recently the outlawed extreme 'engine maps'.
Horner is quoted by Auto Motor und Sport: "We have never adjusted the right height under parc ferme conditions. Neither by tool or by hand."
The report, however, said Horner did not deny the former existence of the hand-adjustable system.
Briton Horner also scoffed at all the fuss about engine maps, insisting world champion Sebastian Vettel "didn't particularly like" the Hockenheim specification anyway.
"So it was a storm in a teacup," he said.