One is the Ventnor Project Group, led by film-maker John Albert, the other is the Chinese Historic Ventnor Group, whose spokeswoman is Rawene resident Wong Liu Shueng.
Mr Albert is making a documentary; Ms Wong is writing a book.
Ms Wong's group has publicly attacked the divers for "disturbing" the wreck, though Mr Albert insists they approached it with utmost respect.
The event in Wellington was to have centred on the presentation to Te Papa of a few items taken from the ship to identify it.
Mr Albert said the day was supposed to have been for the supporters of the non-profit dive project.
Ms Wong said she had proposed that her group also take part, but Mr Albert said that would not have been appropriate.
Items retrieved from the Ventnor remain in the care of the police.