John Key went to meet Hollywood bosses with a briefing from officials saying studio bosses were looking for easier ways to target New Zealanders who downloaded and shared films illegally.
Officials told the Prime Minister Hollywood objected to the $25 fee it had to pay each time a notice warning against copyright infringement was issued and wanted to pay less.
Mr Key's trip to Hollywood came amid political heat over the Kim Dotcom case. An accused internet pirate, Mr Dotcom is facing extradition on charges of criminal copyright violation after an FBI investigation.
He has claimed the case was motivated by the Motion Picture Association of America, the lobby group representing the main studios.
Mr Key's briefing from officials described the MPAA as "highly influential in Washington political circles". He was told its influence meant the group had "played a key role in shaping US trade policy to suit its particular interests".
"Strong copyright protection is seen by the MPAA's members as fundamental to the ongoing viability of the film industry."
The MPAA's members are Disney, Paramount, Sony Pictures, Twentieth Century Fox, Universal Studios and Warner Bros. Mr Key was told: "These film industry giants are strong and vocal proponents of strengthening copyright protection, both within the US and worldwide."
The briefing, released to the Green Party, said the industry's power meant there was an established set of demands around copyright in any free-trade agreement. It included stronger online enforcement procedures, longer copyright terms and restrictions on parallel importing.
He was told the MPAA was the "strongest advocate" of New Zealand's new enforcement regime which saw those found to have downloaded copyrighted material through "peer-to-peer" file sharing sites warned three times against doing so before facing up to $15,000 in compensation through the Copyright Tribunal.
The briefing stated the support came through the MPAA's New Zealand arm - the Federation Against Copyright Theft - which saw the regime as becoming a "gold standard" for similar schemes around the world. Despite the support, Mr Key was told the studios behind the MPAA did not use it because the $25 fee paid to internet service providers to send warning notices was too high.
A recent review of the scheme kept the fee at $25 because lower costs would hurt ISPs, who were forced to pay up to $100 to send each notice. Mr Key was told the MPAA's involvement would lead to an increase in the number of warning notices sent to people and give a "critical mass" that would bring the cost down.
Opponents of the fee change warned cheaper costs could lead to a rise in vexatious complaints.
Internet luminary Nat Torkington told the government body hearing submissions on cost that the fee prevented false accusations.
He said it reduced the possibility of "encouraging willy-nilly accusations in the hopes that some will stick".