Somali taxi drivers in Perth are consuming a locally grown plant that has amphetamine-like effects to get through long shifts, according to research.
University of Queensland Professor Heather Douglas said during her two-year study into use of khat in Australia, many Somali migrants had raised concerns about the number of taxi drivers taking the drug.
Former Ethnic Communities Council president Suresh Rajan, who contributed to the study, said it was common knowledge among the Perth Somali community that many taxi drivers used khat.
Both Mr Rajan and Ms Douglas said it was very worrying because the plant had a similar intoxicating effect to amphetamines and there was no research on how badly it impaired drivers.
Khat, the leaves of which are either chewed or boiled into tea, was planted in many inner Perth suburbs in the 1950s and 1960s.
It is legal to grow but illegal to harvest because it contains the prohibited drug cathinone.
Ms Douglas said some Somalis she interviewed had told her they had stopped driving while under the influence of khat because it had made them aggressive behind the wheel and caused them to rack up speeding fines.
Shadow road safety minister Michelle Roberts called for an immediate investigation into how many taxi drivers were using khat.
Road Safety Council chairman D'Arcy Holman said he would be "surprised and concerned if any taxi drivers were deliberately using substances that would inhibit their driving".
Mental Health Minister Helen Morton said the legality of khat was being considered as part of a national drug law enforcement project.
"I will follow this up to see if there's more WA needs to be doing independent of a national response," she said.
WA Taxi Council chief executive Olwyn Williams said she had not received any reports of drivers using khat.
One southern suburbs man told _The Weekend West _he removed his khat plant last year after being repeatedly threatened with violence by African men who jumped into his backyard to ransack it.
The last publicised prosecution linked to khat was in 2009 when a Thornlie couple were charged with drug dealing after police seized more than 32kg of khat leaves at their home.