An Eastern Cape man out on bail after being accused of assaulting his former girlfriend died after succumbing to injuries sustained in a "high speed" head-on collision.

Andrew Turnbull and two other people died after the gruesome crash on Sunday outside the town of Port Alfred in the Eastern Cape.

“Andrew, our only son and brother to Lindy, passed away in the early hours of this morning (Monday) in PE due to serious injuries from a car accident," his mother Martha Turnbull posted on Facebook early on Monday.

"His friend Ryan Byrne died at the scene. Please I’m begging everyone to please give us time to mourn and to stop the horrible stuff that is being posted on FB. We are heartbroken,” she wrote.