Molewa says Numsa’s claims that government was trying to get away with cheap labour are patently false and she has challenged the union to come up with evidence.
The 301 firefighters returned home this week.
They had gone on strike over a pay dispute just days after touching down in Alberta to help Canadians battle wildfires.
The firefighters were deployed to Canada by Working on Fire (WoF), which is part of government's Expanded Public Works Programme.
Molewa says these programmes are meant to enhance job opportunities and participants are paid according to prescribed guidelines.
