INQUIRIES into the Singapore murder of ICAC witness businessman Tommy Chui To-yan yesterday focused on a car that may have been used to intercept Chui's black Porsche moments before he was killed. Singapore police believe the driver of the red Honda Accord, which has a broken right headlight, forced Chui off the road while he was on his way to a friend's cocktail party in Chinatown. It is understood Chui, 38, was taken away from his Porsche beaten and killed. He then had three eight-kilogram scuba-diving weight-belts tied to him before being thrown into the harbour near Clifford Pier. Police have taken fingerprints from the Accord and removed its licence plate for further investigation. 'We will send Singapore police to Hong Kong if it is necessary,' Inspector Lam Chin Tiak said yesterday. Police revealed for the first time that Chui was beaten and suffocated to death. 'He died of asphyxia. Bruises were found on his body,' Inspector Lam said. Chui, who emigrated to Singapore in April 1993, was to testify in an alleged cigarette smuggling case for the Independent Commission Against Corruption. One of the defendants, Henfrey Tin Sau-kwong, faces corruption-related charges for offences that allegedly took place when he was a Customs officer. Tin, 45, is a friend of sacked ICAC deputy director Alex Tsui Ka-kit. A co-accused merchant, Chong Tsoi-jun, 49, faces two counts of conspiracy to offer advantages in relation to the processing of export permits for cigarettes and the preferential scale of cigarettes from a tobacco firm. A third accused, former Customs officer Yeung Kam-fai, 43, is charged along with Tin and Chong on one count each of conspiracy to export unmanifested cigarette. Chui's coffin, believed to be worth $100,000, was being kept at a secret address last night and under guard.