Victims Lee Yoke Mun, 73, and his wife Lee Kam Lin, 59, were found lying in pools of blood by the man's elder brother about 5am.
It was learnt that the 80-year-old brother had gone to a nearby market to sell fruits with his wife earlier, and rushed home after being alerted by a neighbour about loud noises from their house.
The brother said he found his son, 44, washing blood from his hands at the house's bathroom.
Yoke Mun's body was lying on the floor near the suspect, while Kam Lin's was found inside the house's master bedroom.
Police arrived minutes later and arrested the suspect. A team of police Forenscis Unit officers then conducted checks at the scene.
A neighbour, who declined to be identified, said he heard a loud commotion about 5.30am.
As of 2pm, New Straits Times' attempts to get confirmation and further details from the police went unanswered as Serdang police chief Superintendent Abdul Razak Elias was in a meeting.
