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Police handling of the anti-terror raids is again under fire after officers stormed the home of an Auckland businessman in search of a library card, a Hawaiian shirt, a pair of khaki shorts and a copy of the leaked terror affidavit.

A dozen plainclothes detectives raided the Whangaparaoa property of Vince Siemer on Thursday morning looking for anything connecting him with those accused of taking part last year in IRA-style training camps in the foothills of the Urewera Ranges.

Siemer's wife, Jane, and 13-year-old daughter, Stephanie, were home at the time of the raid and both had their cellphones confiscated.

Siemer claims to have never met any of the accused - who include high-profile Tuhoe activist Tame Iti - but has admitted circulating copies of the 156-page police affidavit to sections of the media and "a couple of political people".

"It [the affidavit] was a bunch of crap. These people were not terrorists. That's why I circulated the affidavit," Siemer said.

"I'm one of probably 5000 people who have this affidavit. Are we all going to be targeted? I'm not a terrorist. This is just Nazi-ism."

The leaked police affidavit includes transcripts of telephone calls and video surveillance footage intercepted by police between March 2006 and August last year.

The affidavit has been widely circulated over the past few months, despite heavy suppression orders around the document.

Auckland lawyer Charl Hirschfeld has criticised police over the raid of Siemer's house, describing it as having all the hallmarks of a "fishing expedition".

"I would have thought this matter would have been sorted out one way or another by now," he said.

"If the police are still trying to substantiate allegations concerned with those arrested, it sounds as though their case is rather on the thin side."

Siemer, who runs a web-based news service, told the Herald on Sunday he believed the raid was in direct retaliation against ongoing criticisms on his website of Solicitor-General David Collins.

"It was just to shut me down," Siemer said.

Siemer was in the headlines last July after being jailed for six weeks after being found in contempt of court for continuing to publish allegations against insolvency expert Michael Stiassny.

The search warrant obtained by police to gain access to Siemer's property was signed off by a court deputy registrar.

In that warrant, police say Siemer is under suspicion of "wilfully attempting to obstruct, prevent, pervert or defeat the course of justice". It goes on to list items of interest to police, which include a blue jumper, grey trousers, an "island-styled patterned shirt", khaki shorts, a V-necked buttoned shirt, computer paper and software, the leaked police affidavit and Siemer's library card.

Detective Superintendent Andrew Lovelock, who is heading the investigation into the leaked affidavit, would not say what the relevance of the items was but stressed the police raid was carried out by the book.

They were examining items of interest taken from the home and would decide later whether charges would be laid.

Because the matter was under investigation, he was not able to say anything else.

Siemer was at a loss to understand the significance of his library card, but thought that the card, and the clothing police were looking for, related to visits he made to the Whangaparaoa Library last November and December.

It was his understanding that a lawyer representing one of the men accused of firearms offences linked to the anti-terror raids had received an email Siemer had sent from a computer at the library during the dates in question.

Siemer said police had obviously seized security camera footage in the hope of connecting that footage with clothing he may have worn on those particular days.

"For more than six hours we were prevented from showering, answering our phone or otherwise having free access to our home. No record was left of what they took and we were left to clean up the mess and damage."

The raid coincides with the arrest last week of three more people on a series of firearms charges relating to October's terror raids. Nineteen people now face charges following last year's controversial police raids.