It has been five and a half years since the nation was shaken by the macabre murder of Dutch billionaire Tob Cohen - a crime as disturbing as it was mysterious.

For days, his sudden disappearance gripped headlines, speculation swirling like vultures over a grim secret.

When things finally surfaced, it was chilling beyond imagination. The discovery of his decomposing body in an underground septic tank on his lavish Kitisuru property.