A member of the Williams crew was knocked to the ground when Stroll departed his pit stall after his second pitstop at Mexico City, but escaped uninjured.

The stewards ruled that the car was "released unsafely" and "in a manner endangering team personnel".

Their statement added: "The stewards determined that the entire pitstop sequence was complete and that the mechanic being struck was as a result of a minor miscoordination at the conclusion of the pitstop sequence.

"Nevertheless, while the contact did not result in injury, the stewards found that it is the obligation of the team to ensure that all personnel are clear of the car before it is released."

Ferrari was fined €50,000 for the Bahrain GP pit incident in which mechanic Francesco Cigarini sustained a broken leg when hit by Kimi Raikkonen's car.

The Mexican GP stewards panel said that incident was compared to the Stroll pitstop when deciding the size of Williams's fine.

"In determining the penalty, the stewards reviewed the incident in Bahrain 2018," the statement added.

"In that case the sequence on the left rear tyre was significantly delayed and not at all completed prior to the car being released, resulting in serious injury to a team member."

Stroll continued without delay and finished the race in 12th.