A bid by US authorities to extradite Mr Dotcom from New Zealand to face movie piracy and racketeering charges is currrently mired in legal wrangling compounded by a domestic spying scandal.
Mr Key also confirmed that studio heads present including the heads of Fox, Disney Warner Brothers, Universal, Sony and MGM studios also "talked a bit about intellectual property, but really more in the context of TPP (Trans Pacific Partnership) and those negotiations".
"Obviously they're making the case that they invest hugely in the creation of intellectual property and it's critically important for their capacity to continue to be able to invest for that intellectual property to be protected.
Mr Key said while the studio heads didn't know exactly what was being discussed in talks to establish the 11 country trade agreement, "they're certainly aware that it's a significant chapter in the TPP and they certainly made us aware it's an important issue to them".
Mr Key said Mr Landau and Mr Cameron both spoke about the benefits and merits of making films in New Zealand during the dinner and a short video presentation from Hobbit director Peter Jackson was also shown.
"From our perspective it was very successful because it gave us a chance to present credible reasons about why New Zealand's a good place to make movies and television", Mr Key said.
Mr Key previously said he would be surprised if studio bosses raised Kim Dotcom during the trip.
In his post cabinet press conference on October 1, he said Google and other US companies had not raised the matter with him during previous meetings.