A union representing medical laboratory workers says members taking part in partial strike action are being sent home without pay.
The company, Southern Community Laboratories, says none of those suspended are involved in Covid-19 testing.
But the union says employees who have been working long hours and extra shifts testing Covid samples are affected.
More than 700 workers at private laboratories around the country have issued strike notices for a 24-hour full withdrawal of labour from Friday, 4th of September.
David Munro is the national advocate for the APEX union.
Southern Community Laboratories declined an invitation to come on the programme.
It said in a statement: "In relation to the partial strikes this week, we are doing our best to work collaboratively with employees who are not performing all of their duties. We have suspended six staff members who have refused to perform duties that are central to their roles (for example, employees in our call centre who are refusing to answer phone calls and none of those suspended are involved in Covid-19 testing)."
"This is out of a total of 1200 employees, approximately 460 of whom are engaging in the partial strikes. We continue to work with the Ministry of Health and the DHBs, keeping them advised on progress and keeping up our commitment on Covid-19 testing."
"As our overall patient volumes since the pandemic are lower than last year (even with inclusion of Covid-19 test volumes), we have continued to maintain a high quality of service during this time, even with the additional demand for Covid-19 tests."