TVNZ has complained to Facebook after the publication of weight-loss ads using stars such as Petra Bagust, Toni Street and Shavaughn Ruakere.
The two Breakfast presenters and Shortland Street actress' images appear in separate advertisements for gyms and a beauty product which claim 13kg can be lost with "two simple steps".
TVNZ spokeswoman Megan Richards said the broadcaster had been aware of the issue for several weeks, although the bogus ads appeared to have evolved recently.
Half a dozen gyms including the national chain Les Mills have been promoted by the ads, while earlier ads were linked directly to the product Duocleanse. Clicking on the link takes the user to the promoted gyms' websites but Ms Richards said all had denied having anything to do with the ads.
TVNZ's legal team had asked the social media giant to remove the ads as it was unpleasant for its stars and clearly a breach of copyright.
"Our view is ... somebody is making money out of this somehow, somewhere but we have not yet established where in the chain this is taking place and where it is."
Bagust's pictures had been in use longer than Street's. Ms Richards said Facebook was investigating.
"They've picked it up but they haven't offered us any resolution just yet either ... Clearly [Bagust] is not happy, we're not happy and we'd like to get it down as soon as possible."
Les Mills reported the ads to Facebook yesterday. National marketing manager Kristin Falconer said the company was disappointed "our brand is being used in this way, and without our knowledge".
Another gym used in the ads, ABSolute Health & Fitness in Dunedin, asked for help from members.
"If you see an advertisement on your newsfeed with a photo of Petra Bagust using our website address, report it to Facebook, it actually takes you to a spam site. We have never asked or wanted any advertising on Facebook."
An Australian Facebook representative asked for comment did not respond.
NetSafe chief technology officer Sean Lyon warned businesses that although Facebook's ability to target particular groups was unlike any other media platform, there were risks.