Thirteen-year police veteran David Tredinnick denied using cannabis saying the positive test was caused by handling wet, sticky cannabis without gloves during a raid.

The appeals tribunal rejected this claim and quashed his bid to get his job back.

In May 2014, the then locally-based Mr Treddinick, took a drug test six days after a raid.

The initial Industrial Relations Commission hearing was told his urine sample initially tested negative for cannabis, but it was sent to a laboratory where it was found to contain 185 micrograms per litre (µg/l) of cannabis, which experts said was considered low. A hair sample tested negative for drugs.

However, Mr Treddinick, who had an unblemished record, was sacked and he then took his case to the Industrial Relations Commission, where forensic toxicologist Dr Michael Robertson said: “Levels associated with recent use of cannabis may exceed 2000µg/l in the day or days following use.”

Yet, Dr Robertson and his fellow toxicologist Dr John Lewis agreed that even that low level was consistent with Mr Tredinnick deliberately using cannabis a day or two before the test.

Dr Lewis, in his report of May 27, 2016 concluded; “In providing this report I have considered the possibility of occupational absorption of cannabis during the operation conducted by Mr Tredinnick on May 28, 2014.

“I have also considered the possibility of contamination from the officer’s load-bearing vest on and after May 22, 2014.

“I am of the opinion that the urine result from May 28, 2014 could not have occurred as a result of either of the above scenarios.

“I am of the opinion that the only explanation for the urine result of 185 µg/L Carboxy-THC is that Mr Tredinnick had used cannabis within a short time prior to the drug test on May 28, 2014.”

Mr Tredinnick appealed the full bench of the IRC, but on Friday his claim was dismissed.

You can read the full case at https://www.caselaw.nsw.gov.au/decision/583e2986e4b058596cba1fd8