Facebook has apologized to an Australian feminist group after blocking an advertisement featuring plus-sized model Tess Holliday in a bikini.

The social network had told the group, called Cherchez La Femme, that the image was rejected because Facebook's guidelines do not allow health and fitness ads to depict a particular body weight as being either "perfect or extremely undesirable," according to a screenshot posted to the group's page.

"Ads like these are not allowed because they make viewers feel bad about themselves," a Facebook ads rep said in the message.

Instead, Facebook suggested an image of someone "running or riding a bike" might be more acceptable.

The ad in question was designed to promote an event the group is hosting called "Feminism and Fat." A spokesperson for the group told Mashable that the 22-year-old model hadn't approved the photo for use in the ad, though members did try to contact her beforehand.

Hours after the screenshot was posted, a Facebook spokesperson said the company had reversed course and apologized for the rejection, which it said was a mistake.

"Our team processes millions of advertising images each week, and in some instances we incorrectly prohibit ads," a Facebook rep said in a statement. "This image does not violate our ad policies. We apologize for the error and have let the advertiser know we are approving their ad."

Cherchez La Femme producer Jessamy Gleeson told Mashable that the group isn't satisfied with the simple apology and would like to see more action on the social network's part.

"It shouldn't take international media attention for Facebook to realise it has a problem with how it is policing women's bodies in its network," Gleeson said in an email. "We would like to see Facebook seriously reconsider the policy that lead to this situation, and consult with feminists and body-positivist activists to rewrite and readdress this policy."

This isn't the first time an advertising entity has landed in hot water over perceived body-type discrimination. Earlier this year, NBC and ABC prompted an outcry when they rejected a Lane Bryant commercial deemed too risqué for their advertising standards.

Updated on Monday May 23, 5 p.m. PST to reflect comments from Cherchez la Femme.

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