Britney Spears did not break state law by allegedly driving with her baby in a forward-facing car seat, her record company says.
Spears recently revealed she was pregnant on David Letterman's TV show
Sony BMG was responding to reports of a photograph of Spears driving in Malibu, California, with Sean Preston, one, in the back facing forward not back.
Spears, who is now pregnant with her second child, was in "total compliance" with Californian law, Sony BMG said.
In February, she was photographed driving with her son on her lap.
The 24-year-old later said she was frightened by paparazzi chasing her but admitted she had made a mistake on that occasion.
In a statement, Sony BMG said state law required that "all children under the age of six or weighing less than 60lbs be in safety seats in the back seat of the car".
It added rear-facing car seats were compulsory neither in California nor many other parts of the US.
"In fact, there are only 10 [states] that require a child to be in a rear-facing car seat, and in two of those states it is not required if the infant is more than 20 lbs. Britney's son Sean weighs over 20 lbs."
Spears achieved global fame at the age of 17, with her number one single Hit Me Baby One More Time, going on to sell millions of albums.
But she has put her music career on hold to bring up her child, releasing her last album - a greatest hits compilation - in 2004.
Spears married her husband Kevin Federline, 28, in September 2004. Sean Preston was born a year later.