POLICE are investigating what is believed to be Perth's first Kronic-related death last night as the WA Government moves to widen the drug ban.

Police said the man was rushed to Rockingham hospital suffering what is believed to be cardiac arrest at about 6.30pm.

The man was unable to be revived and police said they thought he may have been smoking black Kronic just prior to his death.

Police have launched an investigation into the man's death in a bid to determine how he died.

The man's death comes just one week after the State Government vowed to crack down on another 14 synthetic cannabinoids after up to nine people were hospitalised with illnesses linked to the use of Kronic products.

Five cases, reporting severe heart palpitations and high blood pressure, were recorded at Joondalup Hospital last Friday night.

Last week, Mental Health Minister Helen Morton said the Health Department was drafting new regulations to extend the ban within a fortnight.

The substances will become illegal from midnight tonight.

Ms Morton she was most concerned about the possible long-term impact of the substances, including drug-induced psychosis.

``Their heart palpitations, high blood pressure and their general feeling of being very unwell has subsided,'' she said.

``But we will not know and nobody knows because there are no clinical trials to show what the long-term effects of this sort of substance is on your health and in particular you don't know about the potential for this substance to trigger a psychotic illness in a person.

``People are taking a huge risk if they continue to take these substances.''

WA became the first state in Australia to ban synthetic cannabis last month when the State Government added seven chemical compounds to the list of prohibited substances under the Poisons Act. The Federal Government subsequently followed suit.

Last week, police seized samples of a new form of Kronic, called Kronic Black Label, to determine if it breaches the ban.

Australian Medical Association WA president Dave Mountain warned just last week that it was only a matter of time before someone died. He said the State Government had acted swiftly, but the Federal Government was dragging its feet.

``If these substances are known and if there is collaboration between different governments and law enforcement agencies, it should be possible to identify most of the substances that are out there and actually ban them before they become available for use,'' he said, following reports of the nine hospitalisations last Friday.

``These are unregulated drugs with less regulation than normal things in our society like alcohol and milk bread would have more regulations than some of these substances that are coming in and they have serious side effects.

``They're designed to mimic drugs of abuse and we really see no reason why governments shouldn't be ahead of the game.''