Ōtaki MP and Minister of Immigration Nathan Guy has denied allegations of corruption within Immigration New Zealand.
He says visas for foreign fishing crews have been audited correctly.
The comments follow an anonymous letter sent to a Labour MP claiming corrupt practices and a lack of audits for hundreds of visas.
In the letter, someone claiming to be a senior immigration officer says they are tired of institutionalised corruption within Immigration New Zealand.
But Immigration Minister Nathan Guy denies any suggestion of widespread corruption although he says he has yet to read the letter.
Letter says no audits done
But it says no audits have taken place to ensure that minimum wage and labour law requirements are met.
Last year the crew of the Korean boat Oyang 75 walked off the vessel, saying they had worked 40-hour shifts and been abused by officers.
Ms Fenton says audits are there to protect foreign crews. She also says the person also raised misgivings about student visas.
But the Minister says fishing crews have been dealt with properly.
And he points to the Government’s recent announcement that all foreign ships must be reflagged as New Zealand vessels – effectively placing them under New Zealand law – within four years.
That issue is being investigated by Immigration New Zealand.