Workers on foreign-owned fishing boats contracted by New Zealand companies are being forced to sign away their rights to complain about conditions, says an Auckland University researcher.
Dr Glenn Simmons, whose expose of abuses in the fishing industry triggered a ministerial inquiry three years ago, said fishermen had been threatened with financial penalties if they spoke out.
"You can't contract out of New Zealand law, but that's what some of these fishing operators are doing."
Dr Simmons said he was seeing less of the kind of abuse uncovered in 2012, when fishermen talked about being beaten, raped, and working up to 53 hours in one shift for as little as 49 cents an hour.
Many of the worst offending companies had left New Zealand since the rules were tightened.
But Dr Simmons said the financial exploitation was harder to stop, and it was very hard for crew to tell an on-board observer what was happening.
Primary Industries Minister Nathan Guy said he was alarmed and surprised by Dr Simmons' claim, considering the level of oversight now in place including forensic auditing and observers.
"[The workers] need to have an individual New Zealand bank account, they need to be appropriately paid for their services.
"We've got observers on there to make sure they're following New Zealand laws and then we've got the reflagging coming in May next year. So we've done a lot in this space."
From May next year, all foreign-owned fishing vessels operating in New Zealand waters will have to be flagged to New Zealand and come under local labour laws.
According to the Ministry for Primary Industries, three foreign charter vessels have reflagged to date and two are currently going through the process.
A spokesperson for Sealord, one of the country's largest fishing companies, said it worked with three Russian-owned companies, two of which are already registered and one expected to be reflagged early next year.
A spokesperson for Sanford said it expected both its Korean partner vessels would be reflagged by the May deadline.
According to Immigration New Zealand data, 258 work visas were approved for Indonesian nationals to work on fishing vessels in New Zealand waters in the year to June 2015.