"We don't comment on the different commercial arrangements we have," she said.
A Recording Industry Association of NZ (RIANZ) spokesman said they had "nothing to do with it".
"It's really a question for MediaWorks - it's their business and we have no influence over what they do."
He said he was not aware of any of his members complaining about the adverts.
Dotcom said it was un-democratic for content companies to use their ad-buying power to influence the decisions of an independent advertiser.
"It just shows how far the content industry is willing to go just to stop us in our tracks. They don't want this innovation to come out."
Dotcom and colleagues Finn Batato, Mathias Ortmann and Bram van der Kolk were arrested and charged with criminal copyright violation relating to the file sharing website Megaupload and jailed following a high-profile raid on his mansion north of Auckland about a year ago.
He said today the new Mega site was "completely different" to Megaupload and he did not have concerns about Mega's legality.
"There isn't anything illegal about it and, I'll tell you now, there wasn't anything illegal about Megaupload either.
"The only similarity that the site shares is you can upload and download things, everything else around that has been reinvented, the code has been developed from scratch."
Dotcom said the new site would be "even bigger" than Megaupload and would "change the way files are transferred and shared on the internet".
Several hundred people gathered on Queen St as the internet tycoon-turned pop star hosted a Willy Wonka-style giveaway, handing out free "Mega flavoured" ice creams, T-shirts, and tickets to the launch of Mega at the Dotcom Mansion, with winning invitations found at the bottom of ice cream cups.
He told the cheering crowd: "In the dark ages they burned books, the enemies of progress burned books and now today they are burning websites. Mega is going to end all of that"
