The NASCAR star acknowledged this week that Kyle Busch was detained at a Mexican airport late last month after a handgun and ammunition were discovered in his luggage.
Busch was sentenced this month to three-and-a-half years in prison and ordered to pay a $1,000 fine for possession of a gun and ammunition, handed down by a judge in the Mexican state of Quintana Roo.
The federal attorney general's office said the judge decided to allow a conditional sentence and let Busch leave Mexico after paying a bond.
Busch, a two-time NASCAR champion and the most active driver in the Cup Series, acknowledged the situation in a Monday social media post.
I was not aware of Mexican law and had no intention of bringing a handgun into Mexico," Busch wrote.
"When this was discovered, I cooperated fully with the authorities, accepted the penalty, and returned to North Carolina.
"I apologize for my mistake and appreciate the respect shown by all parties as we have resolved the matter. My family and I consider this issue closed."
A NASCAR spokesman said Tuesday that Busch reported the incident to the sanctioning body and received no punishment.