"Some of them are cleaning out a good third of those orchardists' crop."
Sergeant Brown said orchardists suddenly found one side of his tree had been stripped of fruit, with utes often used to take away up to 1000 avocados at a time.
Police had identified two fruit sellers involved in the on-selling of stolen avocados but were still in the process of establishing charges, he said
Rangiuru grower Ron Bailey had not been hit because the private orchard access road ran past his house, but it had not stopped him installing security lights and cameras on the road. "We are all vulnerable ... I can't be everywhere all the time."
He said he was responding to the increasingly organised nature of thefts.
"Unfortunately it seems to be the way society is going. With avocados, it is a case of money growing on trees and some people are quite happy to buy, no questions asked."
Mr Whitehead, the chairman of the Avocado Growers Association and the Avocado Industry Council, said thieves were getting brazen and even striking during the day if they felt it was safe.
Thieves used Google Earth to target orchards without houses and, if there was a house, they looked for a route into the orchard that did not pass near the house.
Mr Whitehead said orchardists were now resorting to fencing off orchards and installing security devices like trip wires attached to an alarm. Thieves tripped an alarm at 2.30am morning on his old orchard but had gone by the time he reached the spot.
"It scared the living bejesus out of them."
He said most raids were in the middle of the night, with one person pulling branches down while the other cut off the avocados. He estimated he lost four to five bins in one year, with each bin holding 330kg.
"For a grower to spend all year growing the fruit and then have it stolen is quite disheartening."
Mr Whitehead said it was a big problem and getting worse.
Retailers who brought suspected stolen avocados at this time of the year risked shooting themselves in the foot because there was so much immature fruit around - it needed paperwork to show the fruit passed the maturity test.
Sergeant Brown said avocados that had no stalks or long stalks were likely to be stolen.
Small business owners were encouraging thefts to continue by on-selling stolen avocados and could potentially be charged with receiving stolen property, with a maximum penalty of seven years in prison.
"Don't purchase stolen fruit. If we work together we can combat this issue."
The avocado industry's leading export supply group, AVOCO, had passed reports to police from growers who witnessed an attempt to sell suspected stolen fruit at Mount Maunganui as well as suspicious activity near avocado orchards north of Tauranga.
AVOCO director Alistair Young said everyone was on high alert for suspicious activity and taking measures to make their crops more secure.
It was incredibly frustrating when growers visited a local store to see suspected stolen fruit being sold cut-price.