The 91-year-old Ecclestone was released on bail and Brazilian media reported that he took a private jet to Switzerland a short time later.
Sao Paulo state's public security secretariat said in a statement that Ecclestone “was detained after federal policemen found a gun in his luggage on Wednesday around 9:30 p.m. in the X-ray area of the Viracopos airport in Campinas.”
Sao Paulo police said in another statement that Ecclestone “claimed to be the owner of the illegal gun, but alleged he did not know it was in its personal luggage.”
Police added the former executive did not want to involve lawyers in the case. He was released after paying 6,060 Brazilian reals ($1,240).
A police report written at the airport and obtained by The Associated Press shows Ecclestone told police he bought the pistol from an unidentified F1 mechanic about five years ago. He said the weapon was kept on a farm in the Sao Paulo state countryside.
Police described the weapon, which was seized, as an unloaded 0.32 LW Seecamp pistol.
Gun possession is allowed in Brazil if owners show they do need firearms for their own security.
Ecclestone has not commented on the incident.
The former Formula One executive, who left the series in 2017, has family in Brazil and is a frequent visitor to the South American nation.
Ecclestone remains a largely influential figure in motor racing, and his standing has also stretched to other sports. The International Ski Federation said in October it is turning to his advice to promote Alpine skiing.
Ecclestone gained a marketing grip on F1 in the late 1970s by selling its TV rights. Four decades later, the British business magnate controlled the sport until his decision to step down. He continues to attend races and meet drivers.
In 2020, he got into a public spat with Lewis Hamilton over the driver's intention to set up a commission to increase diversity in motorsports. Hamilton, a seven-time F1 champion, is the only Black competitor in the series. Ecclestone claimed during an interview on CNN that "in lots of cases, Black people are more racist” than white people.
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