Dennis denies Hamilton finger trouble
Hamilton, whose McLaren dropped through the field last Sunday when his gearbox slipped into neutral, reportedly told the French newspaper La Presse that he accidentally pressed a wrong button on his steering wheel.
The Briton's claim is backed by on-board camera footage that depicts Hamilton's left thumb as pressing a button before he slowed.
But Dennis is on Tuesday quoted as saying: "There was nothing that Lewis did that had any relevance to the gearbox."
Team boss Dennis speculates that the problem may have been caused by a faulty sensor, but insisted that it was a mechanical rather than human glitch.
"The only reason that we did not win the world championship was the gearbox problem," Dennis told reporters.
Hamilton, who had to pause an interview with reporters in his Sao Paulo hotel room on Monday afternoon to throw up, called the incident a "small hiccup" that cost him a place in F1's record books.
"But I didn't wake up this morning thinking 'oh shoot'," he added. "I've just got to get on with it."
Meanwhile, Mercedes-Benz competition director Norbert Haug has indicated that Hamilton's wish for the 'cool fuel' protest to be dropped is unlikely to change the team's decision.
"Those teams had a competitive advantage," Tuesday's Bild-Zeitung quoted him as saying. "We cannot brush that aside."