Businessman Mark Tan Peng Liat had sat "in a daze" and in shock as a paramedic tried to resuscitate his father, a court heard yesterday.

He did not respond when Singapore Civil Defence Force (SCDF) paramedic Elroy Chan asked more than once for help to move Mr Tan Kok Keng, 67, who was lying on the floor, unresponsive.

Tan, 30, has been charged with culpable homicide not amounting to murder for the death of his father. He was originally accused of murder.

He was said to have put his father in a headlock and chokehold after a quarrel between the pair at their West Coast Rise home on Feb 10 last year. The senior Mr Tan was pronounced dead an hour after he was taken to the National University Hospital.

Testifying on the second day of Tan's trial yesterday, Mr Chan said the accused had sat on a chair "in a daze", and did not help to move his father's body when asked. He stood up when asked a second time but still did not help. Tan also had a belated reaction when asked what happened earlier, Mr Chan added.

"What surprised me was, people are usually very pro-active in providing history because it (involves) their loved ones," he added.

After further questioning, Tan told the paramedic he had a quarrel or fight with his father and had pinned the older man on the floor.

After that, he stopped breathing.

When the ambulance arrived, the senior Mr Tan had been lying on the floor in the second-level master bedroom, his face bluish.

Mr Chan said this could mean there was deprivation of oxygen due to the patient not breathing for a while, which could be the result of his heart stopping.

On Thursday, Tan's paternal aunt, Madam Tan Hoon Choo, 72, recounted in court how the elder Mr Tan's maid had gone to her house "hysterical" and crying and asking for help around 5.40pm.

Tan was "pale" and looked "bewildered and lost" outside the house when she hurried over. Both men had a "very good relationship", she added, saying that the elder Mr Tan, who had a black belt in taekwon-do, was proud of his son.

He was also "extremely sensitive" about money matters, said Madam Tan. He had a joint account with his two children containing money left by their late grandfather, but she found out from her niece after the elder Mr Tan's death that his son had not received the money.

The Straits Times understands the accused's position is that his father's death was "accidental" and he had been trying to restrain the older man, who had become violent.