"Through Budget 2018 the Government is committing $8.8m of new operating funding over four years for more labour inspectors and support staff," Lees-Galloway said.
"New operating funding of $4.3m over the same period addresses cost pressures in frontline employment services administered by the Ministry of Business, Innovation and Employment, including the Labour Inspectorate and Employment Mediation Services."
The announcement is welcomed by First Union.
Union general secretary Dennis Maga said it would improve the accessibility of labour inspectors to inspect more workplaces around the country.
"There's presently around 50 to 60-odd inspectors for the whole country so only the worst-case scenarios [are] receiving attention," Maga said.
He believed it would also help repair New Zealand's damaged reputation overseas following reports of migrant exploitation over the last few years.
"This announcement ... will help to rebuild New Zealand's reputation as a safe place for migrant workers to work," Maga said.
"It will discourage companies from believing they can import workers and use them for jobs that most Kiwis wouldn't put up with."
AUT researcher Danae Anderson said the Inspectorate has been underfunded and understaffed for years.
"Rogue employers have long known that the chances of being inspected are extremely low as the inspectorate works on a primarily retroactive basis," Anderson said.
"The funding increase is well overdue."
But because the increase is over four years, Anderson said "whether the funding keeps up with the cases of exploitation emerging day to day remains to be seen".