Members of the "Urewera 18" group threw Molotov cocktail fire bombs and fired semi-automatic weapons at training camps in the bush, court documents show.

Details of the evidence against some of those charged after police raids triggered by the Urewera incidents can be reported for the first time following the release of a previously suppressed judgement.

The evidence reveals what police saw in the Ruatoki Valley between 2005 and 2007, and how officers say they identified people at the camps through the clothing they wore.

The Supreme Court ruled the videos inadmissible because they were obtained illegally so could not form part of the case against 13 people facing firearms charges alone.

The charges against those people were dropped this month.

But the Supreme Court ruled the videos could be used against four others, including Tuhoe leader Tame Iti, who faces the more serious charge of participating in an organised criminal group.

In a September 2009 hearing in the High Court at Auckland before Justice Helen Winkelmann, the Crown successfully argued evidence collected against Valerie Morse, who was facing charges of possession of a firearm or a restricted weapon, was admissible.

Evidence from Detective Sergeant Aaron Pascoe was given to the hearing that film and photographs of a September 2007 camp showed a woman he said was Ms Morse holding an object believed to be a Molotov cocktail.

Det Sgt Pascoe was to give evidence that he believed she threw the Molotov cocktail into an outdoor oven, where police later found remnants of Molotov cocktails.

He concluded the person in the film and photographs was Ms Morse because that person was wearing clothing the same as Ms Morse was seen wearing when she was observed on her way to Ruatoki.

That was the only basis for the identification because in all the images her face was concealed.

The judge said other evidence tended to corroborate the identification.

Two surveillance cameras were set up and showed a group of people "milling about" the area. Some were running down a path towards where the burnt-out oven was later found.

Many people moving in different directions were shown in the video film, and one person could be seen making the throwing motion with an object in his hand.

Photos of a person holding a pistol in various military type poses were said to be of Ms Morse.

Two pistols later seized by police were found to be unable to discharge a shot, although an attempt to modify one appeared to have been made.

Justice Winkelmann disagreed with Ms Morse's suggestion that because only non-firing guns were found, no functional pistols were used.

Also brought to the court was a CD of gunshot sounds recorded on the Tuhoe land in the Urewera Ranges.

Justice Winkelmann found the evidence was relevant to show that guns were used at the camps.