Ten Auckland pharmacies are being accused of failing to pay up to 35 workers the minimum wage and holiday pay, as well as keeping proper employment records.
The Labour Inspectorate has confirmed it has filed a claim with the Employment Relations Authority.
"We take these issues very seriously, and are working closely with Immigration New Zealand to ensure that these matters are dealt with appropriately," Labour Inspectorate general manager George Mason said.
"With the case now going into the ERA, we will not be commenting further at this stage."
The pharmacies' spokeswoman Michelle Boag said the dispute centred on staff not being paid to attend a training programme.
"The claim primarily arises from a professional development programme conducted by the pharmacies, and whether time spent in that programme should be included in employees' work time.
The programme was discontinued last year, she said.
"The pharmacies concerned have attempted to engage with [the Ministry of Business, Innovation and Employment] to resolve any issues regarding the programme and any concerns that had been raised.
"We remain willing to engage with MBIE to address these issues," Ms Boag said.
The claim affected between 30 to 35 employees, she said.
The 10 pharmacies in West and South Auckland were jointly owned by four people: Neeten Bhikha, Kerry Oxenham, Navin Patel and Rakesh Patel, according to Companies Office records.
Rakesh Patel was also the managing director of Nirvana Health, according to its website, which was founded by his parents Kantilal and Ranjna Patel.
Nirvana is the largest independent primary health care group in the country.
Navin Patel, a partner at the Auckland-based accounting firm Dfk Oswin Griffiths Carlton, was listed as a minor shareholder in the pharmacies through an entity called Karthik Muni Limited.
His accounting firm's address was listed as the registered address of all ten pharmacies, as it was for Nirvana Health.
Kerry Oxenham and Neetem Bhikha own several more pharmacies across Auckland.
The pharmacies which the Inspectorate has filed claims against are:
- Avondale Community Pharmacy
- Bairds Rd Community Pharmacy
- Family Care 7 Day Pharmacy
- Mangere Community Pharmacy
- Otara Community Pharmacy
- Ratanui Community Pharmacy
- South Seas Community Pharmacy
- Takanini Community Pharmacy
- Victoria Community Pharmacy
- Waiora Community Pharmacy