Police have advised the public not to pull pranks on the case of William Yau Zhen Zhong, who was reported missing at Putra Heights, Subang Jaya last Wednesday, near here.

Selangor CID deputy chief ACP Rosli Mohd Isa said there had been various calls and texts received by the boy's parents from irresponsible individuals.

"Recently, someone called and demanded a ransom for the missing boy. But hung up when they were enquired about the boy. The parents received a text later saying it was just a prank.

"This is a serious missing child case. We will not hesitate to take stern action against those who do this," he told reporters today.

Last Wednesday, William, the second of three siblings, was reported missing at Jalan Putra Mahkota, Putra Heights, when he could not be found after apparently getting out of the car to look for his parents who went to a shop nearby.