LOS ANGELES — A man driving Kevin Hart’s vintage muscle car accelerated recklessly on a Southern California highway, causing the accident that left the comedian, driver and another passenger seriously injured, investigators said in a report released Thursday.

Jared Black was turning on to Mulholland Highway near Malibu early on Sept. 1 when he accelerated and lost control while driving the comic actor’s 1970 Plymouth Barracuda with Hart and Black’s fiancee, Rebecca Broxterman, as passengers, the report from the California Highway Patrol said.

The car then careened down an embankment and slammed into a tree, the report said. Evidence from an examination of the Plymouth suggested no one had been wearing seatbelts.

“I have nothing but love for Jared and wish him and Rebecca a speedy recovery,” Hart said in a statement released through his attorney later Thursday.

Authorities previously said that Hart, 40, and Black, 28, suffered major back injuries while Broxterman, 31, had less serious injuries.