UPDATED 5.37PM The Government has named the person who will investigate our tax laws, in light of the Panama Papers leak.

Tax expert John Shewan has been put in charge of the independent review and the Government wants answers by June.

LISTEN ABOVE: Tax expert John Shewan speaks to Larry Williams

He's a companion of the New Zealand Order of Merit for services to business, and has been part of the Tax Working Group, as well as chair for PricewaterhouseCoopers.

Finance Minister Bill English said after the Panama Papers were released, they need to know if there are improvements we can make.

Mr Shewan told Larry Williams he'll be looking at what the laws, as they stand, mean for our reputation and whether or not the current framework is robust.

"I think upholding New Zealand's reputation in the international scene is really important - that's basically what the terms of reference are about and I'm completely comfortable with them."

The review will look at record keeping, enforcement, and the exchange of information with other tax jurisdictions.

WATCH: Key grilled on Panama Papers

Transparency International is on board with the Government's plan to get outside eyes to look at our tax laws, but the organisation says one international expert mightn't be enough.

New Zealand chair Suzanne Snively said our reputation is at risk - she said New Zealand has already been referenced thousands of times in the papers, and only 10 percent of them have been released.

"If I were in the Prime Minister's shoes I would probably want to appoint more than one expert, just because quite often experts see different things or have different perspectives."

Ms Snively said the more we're doing to show we're vigilant, the more we'll hold our very important reputation.

She said it impacts the way in which people do business with us, opens up export markets we otherwise wouldn't have access to, and means tourists want to come here because they know people are honest and truthful.

SEE ALSO: Cameron publishes tax records while Key back tracks

Meanwhile, the Government remains adamant that New Zealand isn't a tax haven.

Prime Minister John Key said the rules have regularly been tightened over the years, to make sure we're not easy to exploit.

"In 2006 the previous Labour Government introduced stronger disclosure requirements for foreign trusts. In 2009, we introduced anti-money laundering laws. In 2012, New Zealand signed the Convention on Sharing Tax Information."

Mr Key said international commentary that our rules are weak, is just plain wrong.

"Look, people always make claims, the question is whether they are accurate," he said.

The Prime Minister said it's more relevant that we have 40 double tax agreements and 11 information sharing agreements. 

Revenue Minister Michael Woodhouse said we have a robust tax base and strong disclosure rules, so it's just not right to say we're a tax haven.

But Mr Woodhouse said they'll look seriously at any issues raised in the independent review.