Motorcyclist Ghazali Mohamed Noor was hit by one car and run over by another, but neither driver stopped to render assistance.

The two drivers were yesterday named as potential defendants at a coroner's inquiry into the 47-year-old's death.

State Coroner Ronald Gwee returned an open verdict as the two had chosen to remain silent, and he could not come to a firm conclusion as to which event caused the motorcyclist's death.

But he said that evidence "highly" suggests that contractor Tew Hock Sew, 63, and housewife Lim Ah Mui, 57, had committed traffic offences in the accident which killed Mr Ghazali.

Under the Road Traffic Act, it is an offence for a driver not to stop and render assistance to a person injured by his vehicle.

The accident occurred in Airport Boulevard at about 5.45am on Christmas Day last year.

Mr Tew disregarded a "No Right Turn" sign, at the centre median opening opposite the Airport Police Station exit and made a U-turn. He drove right into the path of Mr Ghazali's motorbike, which crashed into his car.

The package officer with the Singapore Airport Terminal Services (Apron) was flung off and landed in the second right lane.

While he was trying to get up, a Mercedes-Benz, driven by Madam Lim, ran over him.

She did not brake or slow down, going on to pick up her husband at the airport.

The two might have got away if it were not for other road users who witnessed the incident.

Singapore Airlines flight attendant Desmond Tan Tuan Yeow was travelling to the airport in a taxi with two colleagues when he saw Mr Ghazali colliding into Mr Tew's car and Madam Lim's vehicle running him over.

Mr Tan, 33, immediately called 999, while the taxi driver pursued the two cars.

The cabby sounded the horn and flashed his lights at Madam Lim but she refused to stop even when Mr Tan gestured and shouted at her to do so, said a report by Senior Staff Sergeant Tan Chee Sing of the Traffic Police.

Another witness, 22-year-old motorcyclist Mohammed Faizal Hanafi, saw Mr Tew's Toyota Camry hit Mr Ghazali.

He tailed the car and gestured to Mr Tew to return to the scene, which he did about five minutes later after dropping off a Chinese national at the airport.

Madam Lim, however, went home after picking up her husband at Terminal 1. She reported to the Traffic Police eight days later only after being issued a call-up letter.