F1 stewards fined Red Bull's championship leader Max Verstappen 50,000 euros ($57,250) on Saturday after he touched and examined the rear wing of title rival Lewis Hamilton's Mercedes following Sao Paulo Grand Prix qualifying.

The 24-year-old Dutchman, who leads seven-time world champion Hamilton by 19 points with four races left, qualified second for Saturday's 100 kilometers sprint race that determined the starting grid for Sunday's event at Brazil's Interlagos.

After the session on Friday, Verstappen inspected the rear wing elements on his car and Hamilton's Mercedes, touching them with his hands.

Later that afternoon the governing International Automobile Federation (FIA) revealed that Hamilton's car had failed a technical inspection by a matter of millimeters.

The Briton risked being sent to the back of the grid or forced to start in the pitlane for the sprint race. He also already has a five-place grid penalty for Sunday's grand prix due to an engine change.

The stewards said in a statement that Verstappen had breached article 2.5.1 of the international sporting code. The article covers behavior in the secure "parc ferme" area after qualifying.

It stipulates that no unauthorized "operation, checking, tuning or repair is allowed".

Speaking before the verdict, Red Bull Racing Principal Christian Horner said he would be "amazed" if Verstappen got a penalty.

"I think obviously Mercedes' straight-line speed is very impressive, so I think he's maybe just having a look at that," Horner told Sky F1. "Drivers are very inquisitive animals sometimes. We've seen it many, many times."

Verstappen, who has raced with number 33 since starting his F1 career in 2015, admitted on Thursday he would love to race next season with No. 1 on his Red Bull car.

"To be honest, if you don't think about it (title), you don't have any dreams or whatever. So I am just really focused," Verstappen said. 

"A lot of things can happen in four races. We are looking good, but things can change very quickly. I said it after the race in Mexico. I've had a bigger lead already in the championship and that disappeared within two races."

(With input from agencies)