No charges were put to safari operators Clayton Fletcher, 32, of Sandhurst Safaris in North West, Gert Saaiman, 48, of Saaiman Hunting Safaris, and Pretoria hunter Deon van Deventer, 36.
Charges were withdrawn against a fourth man, Kumaran Moodaly of Port Elizabeth, without reasons being given.
The prosecution will apply today for the trial's postponement. The accused will face charges of racketeering, money laundering, various counts of theft, malicious damage to property and contraventions of various provincial conservation Acts, plus the Aviation Act.
The state alleges the accused committed the offences as members of a group consisting of hunters, a pilot, middlemen and buyers who allegedly hunted rhino and traded in horns stolen from the carcasses.
A small aircraft belonging to Saaiman was allegedly used to locate rhino in various national parks around the country.
It was also allegedly used to transport poachers to different national parks, where the rhino were shot and dehorned.
The same aircraft was then allegedly used to transport the horns to Fletcher's farm near Tosca in North West.
In May this year, the Asset Forfeiture Unit seized the accused's houses and Fletcher's seven farms in North West.
The charges are for 17 rhino killed and dehorned in 2005 and 2006 in Kruger National Park, Imfolozi Game Reserve and private game farms near Bela-Bela and Komatipoort.
Three others allegedly part of the syndicate pleaded guilty and were sentenced in 2007.
Kalahari farmers Gideon van Deventer and his brother, Nic, were sentenced to 10 and five years imprisonment, parts of which were suspended. Game farmer Pieter Swart, 24, of Kroonstad, was fined R50000, or one year in prison.