The National Party suspects dirty politics are at play after laptops were stolen from its headquarters, but a business next door was victim to the exact same crime a couple of months ago.

Photo: RNZ / Simon Rogers

An employee of Brunton New Zealand - an accounting software company - told RNZ the Auckland business had several laptops stolen late last year in similar circumstances.

Both Brunton New Zealand and the National Party headquarters have offices on the busy Great South Road in Greenlane.

The two buildings side-by-side are separated by a driveway and have clear signage advertising their offices from the road.

Now both have had three laptops stolen after somebody also jimmied a window open to get entry to National's offices on Sunday night.

The party's deputy leader Paula Bennett said the fact it was an election year couldn't be ignored.

"It's incredibly concerning and I've got to say it looks pretty sinister and suspicious and not a good start to an election year where we'd rather be talking about the issues that affect New Zealanders, but it seems others have other ideas.''

But a woman who works for Brunton New Zealand isn't convinced and told the party so.

"I did tell them, I told the guy at the National office, I said 'well we had the same thing happen to us a few months ago','' she said.

She was surprised when she heard speculation about it being politically motivated.

"Yea, I just wanted them to know I don't think it could be that because we had the same thing happen to us.

"And a lot of businesses it's happening with, that area down there, it's probably quite easy to break into too with those windows,'' she said.

Senior National MP Paul Goldsmith also has an office at the headquarters, which wasn't targeted in the burglary.

Like the Brunton New Zealand burglary, other valuable items including bottles of wine were left behind.

He worries the burglary is the beginning of something much worse.

"We just want to spend election year talking about things that matter to New Zealanders - it's about a growing economy, delivering on promises and so forth and what worries us is that this is a signal about the sorts of politics that will be played this year.

"It's early days, I'm not making any accusation against anybody in particular but to have three laptops stolen from party offices in Auckland is disturbing,'' he said.

Asked whether he thought whoever stole the laptops was after party secrets, he said:

"Well, that's a distinct possibility, so we'll have to wait and see.''

The Labour Party's campaign chair Megan Woods didn't wanted to be interviewed but said in a statement "if it were found to be politically motivated it would be highly concerning and totally unacceptable".

She said, "that's not how politics is done in New Zealand".

Senior Labour MP and Trade Minister David Parker highly doubted it was politically driven.

"I'm quite sure there will have been no involvement from some of the main political parties of which I'm aware.

"I'd be very surprised if there was anything gone wrong there but I suppose it's always possible, as they found in the United States at times," Parker said.

"I can only really speak for the party of which I'm a part and I'm sure we would have no part in it.''

The burglary comes just a week after the headquarters was the target of anti-Chinese propaganda aimed at National MP Jian Yang, who also has an office in the building.

Bennett said it was dangerous to speculate on whether the two incidents were connected, but said it seemed very suspicious.

While police continued their investigations Bennett said the party would look to beef up its security at the headquarters.