The wife and handicapped son of a mechanic who is the main suspect in the gruesome murder of at least four people at their house cum workshop along Jalan Pahang, here, were released.

Perak CID chief, Datuk Goh Kok Liang said the wife, 54 and her son, 17, who were earlier detained and remanded to facilitate investigations, were released due to lack of sufficient evidence against them.

"After we referred the Investigation Paper to KUP (Prosecution Unit chief) we were advised to release the main suspect's wife and her handicapped son due to lack of sufficient evidence against them.

"The police still required further investigations on the main suspect and his eldest son. Therefore we applied for extension of their remand," he said.

However, if there are new evidence related to the murder, police may recall them to assist investigations, he said.

Goh said DNA results from family members of the victims has been received by the police last Monday and police have started investigations.

On Oct 26, the suspects – a 57-year-old mechanic, his wife, 54, and their two sons, aged 20 and 17 – were arrested by police in connection with the disappearance of four victims.

It was reported that the disappearance of a land broker on Aug 28 had led police to a dilapidated wooden house where the four victims were believed to have been beaten to death, their remains burnt and ashes scattered into a river behind the house.

Meanwhile, the Tapah Magistrate's Court today extended the remand order for the main suspect and his 20-year-old son by another seven days.

Magistrate Nurul Nadia Abdul Razak issued the remand order to facilitate police to carry out investigations into the disappearance of a 36-year-old worker at the workshop owned by the main suspect, since Oct 30, 2012.

The mechanic who is the main suspect and his son who is also a suspect, arrived at the court at 8.15am under heavy police presence.

The four victims were believed to have been beaten to death, their remains burnt and ashes scattered into the Ceroh River behind the house but police have yet to release the identities of the victims.