GEORGE TOWN: Heads must roll and police must investigate the approval of a hillside development project linked to Sunday's fatal landslide that killed a doctor.

Penang Gerakan chief Oh Tong Keong said the authorities must determine whether there had been negligence or wrongdoing in approving and monitoring the project, particularly as residents had raised objections years before it was approved.

He called on the Penang government to immediately halt all hillside developments in the state pending a comprehensive review of their compliance with safety requirements and standard operating procedures (SOPs).

"We ask the Penang government to stop all projects first, then form a committee to survey and check whether developers have followed the SOPs for land development in Penang," he added.