Opposition leader Simon Bridges is not worried about the latest National Party leak

Opposition leader Simon Bridges says he is "unfazed" by the latest tranche of internal National Party information that has been leaked to media.

Speaking to RNZ this morning, Bridges called the leaked details of party policies "minor bits and pieces".

An anonymous leaker, who claimed to be a National MP but did not use a parliamentary email address, leaked the information to the Weekend Herald.

It detailed areas of policy National is looking at exploring before the 2020 election, including an income insurance scheme.

The documents were provided to National's front bench between August 14 and September 11.

Bridges said the policy papers were from several months ago and that New Zealanders can "see what's happened over the last two or three months".

"New Zealanders will have a very clear sense of what's gone on in our party over that time."

Asked what the leaks had to do with former National MP Jami-Lee Ross, Bridges said "ultimately, I don't know".

"But I'm not concerned, I'm not fazed. I'm focusing on what Kiwis want."

Ross was put on mental health leave on October 2. He was kicked out of the National Party on October 15 after a PwC investigation into leaked travel expenses revealed he was likely the leaker.

A spokesman for Bridges told the Weekend Herald on Saturday that the policy papers were a number of months old and were sent to "all frontbench MPs at the time".

The leak of the policy documents came after National's internal polls and media talking points, sent to MPs, were also leaked to media last week.

In August, National's internal travel expenses were leaked to Newshub and Bridges launched an inquiry to find out who the leaker was.

Bridges told the AM Show this morning the inquiry was "absolutely" the right thing to do.

"We had a problem, it resulted in an MP being expelled – it was the right thing to do."