An alleged accomplice of a businessman accused of killing his wife's lover took the stand to testify on the second day of his trial yesterday.

Businessman Chia Kee Chen, 56, is accused of killing material analyst Dexmon Chua Yizhi, 37, between the night of Dec 28 and the early hours of Dec 29, 2013.

The alleged murder took place in a van driven by Chua Leong Aik, 67, who is serving a five-year jail term for abduction and causing grievous hurt by dangerous means.

Speaking through a Hokkien interpreter, Chua told the court that he met Chia and his Indonesian worker Febri Irwansyah Djatmiko, who is still at large, on the night of Dec 28, 2013. Chua, a cleaning supervisor, is Chia's friend of more than 20 years.

They parked a van at the third level of a multi-storey carpark at Block 429A, Choa Chu Kang Avenue 4.

Chia, Febri and the victim later went into the back of the van, but Chua told the court he did not know the victim was being abducted at the time.

Chua sat in the front of the van and later drove it to Lim Chu Kang. While driving the vehicle, he heard knocking sounds, heavy breathing and also smelt blood.

Some time between 11pm and midnight, Chua said he stopped the van in the Lim Chu Kang area and got out because he was frightened.

The prosecution's case is that the victim was assaulted by Chia and Febri and forced into the van. And while in the van, the victim was further assaulted and his hands and feet tied up. The extensive injuries the victim sustained to his face and head were fatal.

After Chua got cold feet and left the van, the prosecution believes that Chia drove the vehicle to a live-firing area in Lim Chu Kang to dump the victim's body.

Chia then returned the van, which was borrowed from a friend of his sister-in-law, after he and Febri had allegedly spent an hour washing it at a fish farm.

Yesterday, Mr Peter Douglas Wilson, a senior consultant forensic scientist with the Health Sciences Authority, also testified.

Mr Wilson said he found blood from the victim on the rear wall and ceiling of parking space 290 at the multi-storey carpark, as well as on several areas on the surface of the victim's car. He also found the victim's blood on several spots in the van's rear interior area, as well as on the passenger and driver's seats, and on the steering wheel.

If found guilty of murder, Chia faces the death penalty or life imprisonment. His wife, who testified on Tuesday, was not in court yesterday. The trial continues today.