IPOH, March 7 — Housing and Local Government Minister Nga Kor Ming’s mother received anonymous threatening letters in front of her house in Ayer Tawar warning him to not "challenge Islam”, police have said.

Manjung police district chief ACP Mohamed Nordin Abdullah said today that Nga’s mother, 76, made a police report over the incident at around 10.15am today.

"The woman, who is a retiree, noticed various letters in front of her house warning Nga to not challenge Islam when she wanted to leave the house at 7.30am today.

"The complainer believed that the words in the letters have bad intentions,” he said in a statement.

It is unsure what prompted the threats.

Mohamed Nordin said the case is being investigated under Section 507 of the Penal Code for criminal intimidation through anonymous communication.

The said Section carries imprisonment up to two years or a fine or both if convicted.

He said that police are still in the midst of an investigation and the cause of the incident is yet to be known.

"Efforts are taken to trace the perpetrator,” he added, urging the public to not make any speculations that would affect the investigation of the case.

"Those with information over the incidents are urged to share it with the investigation officer Inspector Fariq Nazmi Mohd Mustafa at 013-3317099,” he said.

In January, Nga’s cousin Datuk Ngeh Koo Ham also faced a similar issue after his house in Ayer Tawar came under an arson attack which damaged three cars including a Mercedes E300 which was almost completely razed, a Honda CRV and Toyota Hilux which were partially burnt as well as the house’s porch roof.

The Beruas MP and his wife were reportedly asleep during the incident before a passerby rang their doorbell and alerted them of the fire.

Ngeh said he strongly suspects the incident to be linked to his remark last month suggesting that non-Muslim legal experts be included in the committee to study the conflicts between Shariah laws and the Federal Constitution, which he said had been distorted by Islamist party PAS and its ally Parti Pribumi Bersatu Malaysia.

Ngeh has since forgiven the perpetrator and suggested the individual could have been instigated by others into committing the crime.