Officers also found $14,000 in cash stashed inside the van, as well as thousands of dollars worth of cannabis, morphine and Ritalin.
Greer, of Bryndwr in Christchurch, earlier pleaded guilty to charges at Christchurch District Court that between January 1 this year and May 24, Greer "did enter into a dealing'' with two girls under the age of 18 for the purpose of sexual exploitation.
He also admitted supplying cannabis, as well as three charges of possessing cannabis and the Class B controlled drugs morphine, and Ritalin.
Police said said Greer's digital camera was found with 17 photographs of six different females in "various stages of undress exposing their genitals or breasts''.
Only two of the victims have been identified, with the ages of the others unknown.
Text data recovered form Greer's cellphone established he had sold cannabis to 20 "school-age students'' over a five-month period.
A district court judge earlier sent Greer to the High Court for sentencing where the penalties are higher. Today, Crown prosecutor Marcus Elliott said it was serious offending that "really does touch a nerve in the community''.
None of the young victims wanted to supply victim impact statements, the court heard.
Defence counsel Kirsten Grey said that while the community may view it as "abhorrent'' offending, it was not a sophisticated drugs operation.
His family was supporting him, and his children had suffered abuse and taunting by other kids, Ms Grey said, which Justice John Fogarty thought was unfortunate and unfair.
The judge said the supply of cannabis to teenagers, who brains have not yet fully formed, can have "very serious consequences'' for them.
The drug can cause demotivation for teens who are at a stage when they need motivation to get on with their lives, while for those at risk of mental illness, science suggests that by taking cannabis can more than double the risk.
In jailing Beria for four and a half years, Justice Fogarty said: "The long term effects on the community of supplying cannabis ... to students is very serious.''