The Commerce Commission is investigating PGG Wrightson over the fees the rural services firm, which is controlled by China's Agria Corp, charged during the implementation of a national livestock tagging programme.
The antitrust regulator will look at fees charged during the adoption of the National Animal Identification and Trading Act 2012, commonly known as NAIT, the Christchurch-based agricultural company said in a statement.
The commission believes Wrightson breached the Commerce Act and will "seek a pecuniary penalty from PGW".
"The introduction of the NAIT programme was extremely challenging for the livestock industry and PGW committed a lot of effort and resources into making its implementation as effective as possible," chief executive Mark Dewdney said.
"PGW considers that the NAIT programme is an important initiative to help protect New Zealand farming's key role as a primary producer and exporter."