PETALING JAYA: The police have collected 228 deoxyribonucleic acid (DNA) samples from residents at Idaman Apartment, Damansara Damai here as part of the investigation to search for the killer of six-year-old autistic boy Zayn Rayyan Abdul Matiin.

Selangor police chief Datuk Hussein Omar Khan said the large-scale operation, which involved house-to-house checks and the collection of DNA samples from the residents began yesterday, and would continue until today.

"As of this morning, 5,628 people and 2,484 housing units have already been checked. There are 18 residential blocks in the area.

ALSO READ: 'Mommy will try to be strong': Zayn Rayyan's mother shares cherished moments on Instagram

"The rainy weather (in the morning) has slowed down the search operation and the handing over of evidence to the police," he said when contacted by Bernama on Sunday (Dec 10).

He said 278 police officers and personnel from various units were involved in the operation.

ALSO READ: Zayn Rayyan murder: K-9 units brought in to search for new leads

Meanwhile, checks by Bernama at the apartment today found that the police had deployed two sniffer dogs (K9) - Ricks and Gucci - from Bukit Aman and the KLIA district police headquarters to check a store and houses near where Zayn Rayyan's body was found.

After being reported missing on Tuesday noon in Damansara Damai, the child was found dead in a stream near his residence the following day, about 200 metres from his apartment block in Idaman Apartment, Damansara Damai.

Meanwhile, the deceased's grandfather, Zahari Mohd Reba, 55, when met at their home in Idaman Apartment denied that the death of his eldest grandson was due to revenge.

ALSO READ: Idaman Apartments Residents living in fear after Zayn Rayyan’s murder

According to Zahari, his son Zaim Ikhwan and daughter-in-law Ismanira Abdul Manaf have lived in the apartment for the past three years.

"Their daily routine is to go to work and come back home. They only know the neighbours living in front of their apartment. They harbour no grudges against anyone," he said. – Bernama