Armed robbers held up a Mercedes Formula One team minibus outside the Brazilian Grand Prix circuit in Sao Paulo on Friday night but nobody was hurt, a spokesman said.
"We can confirm that a team minibus was robbed at gunpoint last night leaving the circuit," he said.
"Valuables were stolen but most importantly everybody is safe and uninjured."
Hold-ups are a known risk for teams in Sao Paulo and around the Interlagos circuit, with drivers travelling to and from their hotels with police escorts and in cars with bulletproof protection.
Britain's Jenson Button was the victim of an attempted robbery in 2010, the year after he won the title with Brawn GP, but the police driver smashed his way through traffic to escape when the gunmen were seen approaching.
Mechanics and other staff travel to and from the track by minibus and are advised against wearing branded team clothing away from the circuit.
A Mercedes team member was also robbed at gunpoint in Mexico last year while travelling by car from the airport to his hotel.
Mercedes have won both of this year's championships for the fourth year in a row with Lewis Hamilton arriving in Brazil as a four-times world champion.
Sunday's race is the penultimate round of the season.