It's all part of how Wellington police broke The Lord Of The Rings movie piracy case.
Since last month three men, whose names are suppressed, have been arrested and charged over missing footage, props, scripts and costume designs from Peter Jackson's $360 million movie trilogy.
Wellington police launched Operation Piece after being contacted by Jackson's Wellington film company Three Foot Six in May. It appeared someone was trying to sell "a piece" of the movie via the internet.
Detective Dave Sayers said police were told the seller had been contacting people in New Zealand via e-mail to unload it. In a first for Wellington police, Mr Sayers spent about six weeks using an alias to negotiate via e-mail with the mystery seller before he was arrested.
Mr Sayers – pretending to be a South African called Richard van Heerden – contacted the man saying he was interested in buying footage. The man offered to sell two video tapes of quality footage from the film – including one 90 minutes long and the other 45 minutes – for $180,000.
"We wanted to bring him out of the woodwork," Sayers said. "But he was very security conscious. He'd keep changing his e-mail address every couple of days...He was using a variety of addresses to send e-mail (from) including home and internet cafes."
Mr Sayers said police used the expertise of the FBI and the Santa Clara County District Attorney's office in California to narrow down who the mystery seller was. Mr Sayers then bought 1 minute of footage for $10,000. Once the seller had received the money, police were able to quickly pin down who it was by tracking the cash, he said.
Next, he negotiated to buy the remaining footage for $170,000 in cash. The man arranged for an exchange in the lobby of an Auckland hotel on June 24.
A police officer posed as the buyer only to find that the man had instead got a courier to carry out the exchange. Mr Sayers said their suspect had told the courier he was a private detective and the video was footage of a politician's wife having an affair. Police persuaded the courier to take the now empty briefcase to the man who was waiting nearby and police pounced.
Mr Sayers said the man was stunned he'd been caught. "He was nervous. He was obviously paranoid, but he had no idea (it was a trap). He thought he was in the money. With all those precautions he took we still caught him."
Mr Sayers said police were surprised to find the briefcase had been lined with tin foil. The man wanted to thwart any chance of a tracking device being planted on the case, he said. "Not that it would work."
Operation Piece was unusual for Wellington police and not only because it was dealing with Hollywood and the FBI, Mr Sayers said. Police had to know about the tougher American copyright laws affecting film footage, as well as New Zealand's. It was also the first time most of an investigation was done via computer, negotiating with a suspect by e-mail.
With a large film crew, secrecy was essential and that was why they never ventured on to the sets. "It had to be done on the hush or it would have got out," Mr Sayers said.
About 17 video tapes were recovered after the man was arrested. Following the other two arrests police were certain they had recovered all copies and none had been sold.
More people could be arrested in relation to thefts from The Lord of The Rings, its producers say.
Publicist Claire Raskind said investigations were continuing. "While we believe we have secured all of our missing property, there are other suspects involved in these cases who may ultimately face prosecutions. We continue to work closely with the New Zealand police and we appreciate their dedication and help in resolving these matters".
The thefts of props and footage follow intense interest in any scrap of information about the top-secret film project. The film company has zealously guarded any release of unapproved information, including restricting access to sets and information about the film. All cast and crew have to sign a confidentiality agreement.
Auckland-based fan Erica Challis, New Zealand editor of the fan website TheOneRing.Net was charged with a trespass notice in January from entering sets, although she said she hadn't been on any. A week later the film company invited her on to the set.
Last month, it moved to stop bidding on a sword - claimed to be from the set - on a US-based Internet auction site Ebay. It had attracted bids up to $4250.
Fan websites also claim at least one specially designed film jacket, a gift to some crew members, was sold via the internet for about $1500.