Hollywood lobbyists raised Kim Dotcom's case with Prime Minister John Key at a dinner in Los Angeles this week.
Mr Key left for California on Wednesday on a Film New Zealand-sponsored trip to promote New Zealand's film industry.
He was invited to a dinner at the home of Jon Landau, the business partner of Titanic director James Cameron.
Other guests included the heads of every major studio and Motion Picture Association of America (MPAA) chief executive and former senator Chris Dodd.
Mr Dodd is known to be close to US Vice-President Joe Biden and has been vocal in his opposition to Megaupload founder Dotcom.
In August he said shutting down Megaupload had had a "immediate and positive" effect on the marketplace.
Before he left, Mr Key had said he did not expect Dotcom to be raised during his meetings in Los Angeles.
Labour deputy leader Grant Robertson said that was "inconceivable".
Mr Key confirmed the internet mogul was raised.
"The studios haven't, Chris Dodd did and he really raised it in passing."
Mr Dodd noted that the case was ongoing in New Zealand but did not ask for an update or help, Mr Key said.
"It wasn't a long discussion but he raised it."
Some studio executives raised general intellectual property issues in relation to the Trans Pacific Partnership trade deal.
Mr Robertson said the fact that it was discussed would add to Mr Key's embarrassment over the issue.
Labour wants a full inquiry into the Government handling of Dotcom.
US authorities closed the Megaupload website and Dotcom and his associates Finn Batato, Mathias Ortmann and Bram van der Kolk were arrested in January on piracy, racketeering and money-laundering charges, which they deny.
The US is seeking to extradite the four men, Dotcom and van der Kolk are New Zealand residents.