The plot thickens. A 17-year-old neighbour has been arrested at midnight on the suspicion of his involvement in the murder of a family of four that shocked Sarawak.

The motive is highly believed to be just housebreaking and theft that gone wrong.

The youth was arrested at 12 midnight and police seized the murder weapon, a sledge hammer with blood stain in his house. Police are combing the Kemuyang dumpside for more evidence.

At 3 am, police also pulled in his mother, a brother and sister to help in the investigation. The suspect's father is working in Papua New Guinea.

A 48-year old neighbour who was detained earlier has been released.

Police also arrested the deceased wife, who was detained for seven days and she is expected to be released once the remand order expired.

When contacted, a very tired Sibu OCPD ACP Shafie Ismail who had been awake the whole night said he was very pleased and happy with the latest progress.

He said the crime is solved and added that a 17-year old youth had been arrested.

He said the deputy commissioner will be in the town to give a press conference later.