The government is cracking down on loan sharks after a couple that was harassed by illegal money lenders allegedly killed their three sons and then attempted to commit suicide.

Deputy Internal Security Minister Fu Ah Kiow said that a new regulation requiring users of pre-paid mobile phones to register by Dec 15 would help authorities detect illegal money-lenders.

Currently, their business cards which are displayed on buildings, houses and vehicles only carry numbers of unregistered handphones in order to evade detection, he told the state Bernama news agency late today.

"We hope after Dec 15, the deadline to register pre-paid handphones, we can detect them easily," he said.

Terrorised by loan sharks

Last week, a Kuala Lumpur couple who said they were terrorised by loan sharks for unsettled debts allegedly killed their three children by forcing them to swallow poison.

They slashed their wrists in an attempt to commit suicide, but were taken to hospital where they recovered.

The case unleashed a storm of media coverage and criticism of loan shark activities.

Fu said that most victims of harassment and threats by loan sharks do not lodge reports and refuse to identify the loan sharks for fear of being harmed, making it impossible for police to take action.