TV interview led to drug raid on shop

Opposition Leader Mark McGowan has been drawn into the trial of an alleged synthetic marijuana dealer raided the day after he spoke out against the Labor leader's stance on the chemical cannabinoid.

Father-of-four Michael Neasmith is charged with seven counts of possessing and attempting to possess drugs with intent to sell or supply after detectives found kilograms of various brands of synthetic cannabis at his Warnbro shop in November 2012.

Numerous packets of Venom, Noah and King of Kronic were seized and tested, with prosecutors telling a District Court jury the plant material had traces of three synthetic cannabis compounds - AM2201, UR144 and XLR11.

The raids on his shop Frav came a day after Mr Neasmith was asked in a television news item about Mr McGowan's opposition to Venom.

Mr Neasmith said on camera that Mr McGowan was "grandstanding" and using synthetic cannabis as an excuse to criticise the Government.

He said he knew the substances had a "chemical kicker" that could get you stoned, which prosecutor Raymond Soh said proved Mr Neasmith knew they were illegal.

"He knew they were synthetic drugs that mimicked the effect of cannabis," Mr Soh said. "He took the risk and didn't care about the consequences."

In several raids, police found bags of synthetic cannabis estimated to be worth $60,000 to $70,000 at Mr Neasmith's shop and at a warehouse in Port Kennedy. They also intercepted three posted packages of similar material sent to Mr Neasmith from wholesalers in NSW.

Mr Neasmith's lawyer Malcolm Ayoub said those wholesalers gave written assurances the material was legal and expert evidence would argue that at least some could not be classed as synthetic cannabinomimetics.