KEY POINTS:
New Zealand is seen as a "soft touch" for Asian crime syndicates smuggling in illegal workers, a researcher says.
Labour-starved areas such as the top of the South Island and Hawkes Bay are prime targets for syndicate bosses, known as "snakeheads", who smuggle in workers to meet the demand in orchards and vineyards.
However, the thousands of illegal workers may end up anywhere in New Zealand where there is work available.
Criminologist and former Nelson policeman Andrew MacDonald researched the problem in the Tasman area after police identified it as a priority. He warns that it will only get worse unless addressed.
"The syndicates are fluid, but our response is quite bureaucratic, so we are always behind the eight ball."
There are believed to be 20,000 illegal immigrants in New Zealand.
In Tasman and Marlborough, the long coastline makes it very difficult to prevent ship-jumpers. "Our isolation is a blessing and a curse at the same time," says Mr MacDonald.
Workers, many from China and Vietnam, pay syndicates to be brought to New Zealand to work. If caught, they are often threatened to keep quiet.
"And in a more sinister way, people enter into contracts and find they have to pay more money and threats are made to their families back home in China or Hong Kong that they may be harmed."
Nelson MP Nick Smith said many orchardists faced the dilemma of letting crops rot or relying on "dodgy immigration practices".
Immigration requirements were too difficult for employers seeking labour, and this gave criminal gangs an opportunity to get a foothold by proving an easier alternative.
Department of Labour spokesman Arron Baker said there had been instances of contractors co-ordinating ship-jumpers and employers on shore, but this was considered an illegal labour scam "rather than anything more sinister".
Prosecutions could be taken, but this could be difficult when witnesses were abroad, contractors were transient, and evidence was difficult to get.
Indonesian Deny Setiadi was sentenced to 4 1/2 years' jail last June for organising people to enter New Zealand and work unlawfully in Napier.
Vietnamese national Thu Huynh, of Nelson, faces 16 charges of aiding Vietnamese workers to stay in New Zealand illegally or breach work permit conditions.
Eight deported workers returned to New Zealand to give evidence to the Nelson District Court about Huynh.
TRAFFIC IN PEOPLE
20,000 - estimated number of illegal immigrants in New Zealand.
$50,000 - estimated cost of each illegal immigrant to taxpayers.
