His lawyer R. Sivarasa said the car carrying Anwar had to brake sharply to avoid an oncoming car, causing another escort car from behind to knock into it.
A prison doctor who examined Anwar said the opposition leader was “shaken up”, said Sivarasa, and was given pain killers.
“The car carrying Datuk Seri suffered damage mainly to the back of the car,” he added.
Anwar is serving a five-year jail term after the Federal Court upheld a conviction on sodomy involving his former aide, Mohd Saiful Bukhari Azlan.
Anwar was admitted to hospital on Sept 19, on the eve of the anniversary of his dramatic arrest on Sept 20, 1998.
His daughter Nurul Izzah Anwar said her father was warded due to his erratic blood pressure, as well as to undergo a routine physiotherapy for an old shoulder injury.