Horner insists that Red Bull did not cheat during Singapore Grand Prix
In the wake of Vettel's performance at the Marina Bay Street Circuit, during which he opened up a 30-second gap over 15 laps to ensure he could make a final pit stop without losing his lead, suspicions have been raised as to how such a display was achieved.
Vettel even joked in his media session ahead of this weekend's Korean Grand Prix that his car was running with a different traction control system that aided his 32-second triumph over Fernando Alonso.
Lewis Hamilton has claimed there is nothing Mercedes can do to match Red Bull, adding that "the last time I was able to put the pedal down that quick was 2007 when we had traction control".
Hamilton was far from suggesting traction control was at the heart of Vettel's cruise under the lights, instead merely highlighting just the speed of the current Red Bull.
For his part, Horner could only smile at suggestions his team were up to no good as he said: "The electronic controls inside the cars are so tightly governed.
"The setting in both cars were absolutely identical, and they fully comply with the FIA rules.
"So any suggestion of traction control is purely either mischievous on behalf of the others, or wishful thinking.
"You would be fairly stupid to introduce traction control on to a car which is governed on a single ECU that is through a tender of the FIA and that is scrupulously checked by the FIA.
"I cannot image any team in the pit lane would do it.
"The problem is Sebastian's performance was so dominant in Singapore it will inevitably raise questions as to how it was possible.
"Other teams will be looking inwardly, and the easiest conclusion to come to is 'They (Red Bull) must be cheating', but these things are so tightly controlled it is impossible.
"The facts are he (Vettel) drove an incredible race in Singapore, he had incredible pace. He maximised the most out of the car, and was a driver at absolute peak form.
"Is it a distraction? No. Will we lose any sleep over it? Absolutely not."
Vettel, however, has made it clear Red Bull had a trick up its sleeve in Singapore, and now it is for their rivals to discover what.
"We were playing around quite a lot with it in practice, but the first time it worked was in the race," said Vettel.
"I was quite confident other people would never figure out how we did it.
"We are pretty proud of the system we have because other people will never figure out how we've done it."