A businessman originally accused of a far more serious charge was sentenced to a year's jail yesterday for committing a rash act that led to his father's death.

Mark Tan Peng Liat was also fined the maximum $5,000 after pleading guilty in court to a separate charge of being in possession of 13 air pistols.

Tan, now 31, was charged with committing culpable homicide not amounting to murder after he put Mr Tan Kok Keng, 67, in a necklock and a chokehold in their home in West Coast Rise on Feb 10, 2015.

But after a nine-day trial, District Judge Eddy Tham found him guilty on June 8 of the reduced charge.

One of his lawyers, Mr Ammar Lulla, told the court yesterday that his client will appeal the conviction and sentence for the rash act.

The prosecution had earlier filed a notice of appeal against Judge Tham's order to alter the charge from an offence of culpable homicide to one of causing death by a rash act.

The prosecution will also be appealing against yesterday's sentence.

During the trial, the court heard that Mr Tan Kok Keng discovered his son had been withdrawing large sums from their joint account without telling him, and he wanted to confront him about it. When Tan returned home, his father accused him of stealing his money. This led to a scuffle in the older man's bedroom and bathroom on the second floor of the semi-detached house.

In his grounds of decision on the sentence yesterday, Judge Tham said Tan had restrained his father with an armlock around his neck. He also pressed the fingers of his other hand in a "V" at the older man's neck for a better grip.

He said: "The combined effect of both locking mechanisms had exerted a significant amount of force on the deceased, resulting in visible bruises around the neck as well as a fracture of the thyroid cartilage."

However, the judge noted that Mr Tan Kok Keng was the one who first used violence on his son.

He said: "The accused was in a volatile situation of trying to fend off an enraged father who was much older than him in age but who was said to be very fit and a holder of a black belt in taekwondo.

"His level of consciousness of the risks involved in deploying such a restraining act would be of a lesser degree than someone who was not in that situation."

During the trial, the court heard that Mr Tan Kok Keng's Indonesian maid, Ms Sumarti Dwi Ambarwati, had rushed to the nearby home of Mark Tan's aunt, Madam Tan Hoon Choo, to tell her about the fight.

In July last year, Madam Tan, 72, testified that she hurried over to their house. Mr Tan Kok Keng was lying inside face up with his mouth open. An ambulance rushed him to the National University Hospital, where he was pronounced dead.

Yesterday, Deputy Public Prosecutor Kumaresan Gohulabalan said police officers who went to the Tans' house that day found the 13 air pistols in Tan's bedroom and study. They also found four containers and two zip-lock bags of pellets.

Tan said in his police statement that he and his father had bought the air pistols during their trips to Malaysia and Thailand. He had used them to shoot plastic pellets at home for his own amusement.

DPP Kumaresan said air pistols can cause injuries when misused.

Tan was offered bail of $50,000 pending the appeals.