New Zealand's first human trafficking trial has been described as a massive learning curve for Immigration New Zealand.

Human rights campaigners believe the landmark trial of two men accused of human trafficking charges, will be the first of many.

A jury found brothers, Jaswinder Singh Sangha, and Satnam Singh not guilty of bringing 18-Indian nationals into New Zealand by deception at the High Court in Nelson yesterday.

The pair allegedly charged each of them $33,000 for a two year visas, and jobs in Blenheim that never eventuated. 

The jury returned not guilty verdicts on charges of arranging the entry of people into New Zealand by coercion or deception.

But Jaswinder Singh Sangha and a third man, Kulwant Singh were found guilty of supplying false statements to a refugee status officer.

Stand Against Slavery CEO Peter Mihaere believes migrant exploitation is a growing issue in New Zealand and that anecdotal evidence suggests it's not an isolated case.

He thinks the not-guilty verdicts are the result of insufficient corroborating evidence.

"There are going to be more cases and there will be more charges, and I would say that the more that we are able to better gather information, we'll get stronger and better at it."

Mr Mihaere acknowledged there's been a lot for authorities to learn from the case.

"One of the issue that came up glaringly short in this process is the lack of resources. Whilst more resources are being put into this, I think a significant amount of resources need to be considered for us to really battle this issue."