A trial is due to start in the Hastings District Court on Monday for four businessmen facing serious charges under the Immigration Act.
They are accused of conspiring to assist illegal immigrants to live and work in New Zealand between September 2004 and December 2006.
Police in Hastings arrested them in December 2006 following a Labour Department operation in Hawke's Bay and the Nelson Marlborough regions.
Information was gathered on employers suspected of assisting overstayers and ship jumpers to work on orchards and vineyards.
The Crown intends to call 36 witnesses during the trial, which is expected to last at least five weeks.
Three of the men are described as company directors.