The father of the 34-year-old Singaporean driver, arrested in connection with the Central Expressway (CTE) crash that killed a trainee pilot, his South Korean girlfriend and her parents last week, has spoken up, albeit briefly.

The New Paper (TNP) reported on Friday that the elderly man said his son, Mr Toh Cheng Yang, had "done a great wrong". "We don't know how to apologise to everyone," said the father, who was not named in the report. "We're afraid that if we say more, we might make things worse."

Singaporean Amron Ayoub, 23, his girlfriend Jamie Song Jisoo, 24, her father Song Jung Woo, 56, and mother Kim Mee Kyung, 54, were killed on National Day after a Honda slammed into them as they were attending to a flat tyre on the CTE.

Mr Amron had pulled over on the chevron area earlier after he felt the puncture to his Toyota. Ms Song's older brother Seoung Hwan survived the crash only because he was at the side of the car jacking it up.

Mr Toh was later arrested for dangerous driving causing death and has since been released on bail. Police said investigations are ongoing.

His brother-in-law, who was also not named, told TNP that Mr Toh, who was injured during the accident, is recuperating but not at home.