Police used a transcript containing mistakes as part of their application for a search warrant to intercept the phone calls and emails of senior Switched on Gardener staff.
Detective Jamie Woods told Auckland District Court today that a conversation between Switched on Gardener general manager Peter Bennett and an undercover police officer was included in a police affidavit.
The conversation, read to the court, quoted Bennett as saying: "They come in and buy blunts, they don't buy grow gear, they just buy blunts."
But the version included in the police affidavit and presented to the Auckland High Court to obtain a search warrant replaced the word "blunts" - a tobacco leaf used to smoke marijuana - with the words "clones" and "plants".
Mr Woods, the officer in charge of files, said the transcript was just one of 60,000 documents contained in hundreds of folders of documents that filled about 10 bookcases.
He said the recorded conversation was initially transcribed by a non-sworn police staff member.
It was later reviewed by the undercover police officer and corrected but senior police officers were unaware of the changes and used the original when they applied for a search warrant to allow them to listen into phone conversations and monitor the emails of senior Switched on Gardener staff.
Mr Woods pointed out that the affidavit to the court made it clear that police were relying on "draft transcripts".
Bennett, Switched on Gardener owner Michael Maurice Quinlan, two of Quinlan's companies, business development manager Ricky Cochrane, distribution manager Andrew Barry Mai and South Island manager Paul Kenneth Barlow have denied charges of belonging to an organised criminal group and supplying equipment used to grow cannabis.
Under cross-examination from Quinlan's and Bennett's lawyer Paul Davison QC, Mr Woods agreed that the transcript with mistakes had Bennett talking about what appeared to be cannabis plants.
He said had senior police known that the transcript contained mistakes, they would have corrected them.
Mr Woods was the last of the Crown witnesses in the case which is now in its seventh week. He also gave evidence about a string of Switched on Gardener employees who have already been convicted and sentenced in courts around the country for supplying equipment for growing cannabis.
The Crown says Switched on Gardener was a "one stop shop" for cannabis-growing equipment.
There has also been evidence of undercover police officers buying marijuana plants from shop staff.
But in his brief opening for the defence, Mr Davison told the court that Quinlan and the senior staff were mindful of the law.
"If they had knowledge of what was going on, it would have been stopped."
He said the defence would call evidence to show that Quinlan's business accounted for every dollar that crossed the counters in its 16 shops around the country.
The court also heard from defence witness Zeljan Unkovich, a lawyer who in 1999 represented a Switched on Gardener employee arrested after police raided the Newmarket Switched on Gardener shop.
Mr Unkovich, who has since retired, told the court that the charges were eventually dismissed and the court ordered police to return a collection of marijuana-themed magazines and pay $15,000 in costs.
The trial continues.