Employers struggling to fill skilled jobs are finding an increasing number of employees have drug problems.

LISTEN ABOVE: Mike Hosking talks to the CEO of the Drug Detection Agency, Kirk Hardy, about how big of a problem drugs have become in the workforce.  

140,000 workplace drug tests were conducted last year.

Just over 13 percent tested positive for methamphetamine use - a five percent increase on the previous year - and more than 80 percent of tests revealed cannabis use.

New Zealand Drug Detection Agency boss Kirk Hardy told Mike Hosking it was picked up in random testing.

"And that comes with a wide range of work places these days, it's not traditionally how it used to be which was transport, forestry, etc. We're seeing a lot of it in tourism, hospitality and professional services now as well."