Facebook has lost its bid to stop a lawsuit by a 14-year old girl whose naked photo appeared on the platform.

The girl, who cannot be named because of her age, is suing Facebook (FB) and the man who repeatedly posted her photo on the social network.

A judge in Belfast, Northern Ireland, rejected Facebook's request to dismiss the case on Monday, meaning it will now go to a full trial.

The company argued in court that it took the picture down on more than one occasion as soon as it was notified. The girl's lawyers said Facebook should have prevented republication of the photo by using a process to identify and track the image.

Back in 2011, Facebook said that it uses Microsoft (MSFT) technology called PhotoDNA to detect child exploitation material. The tool can prevent photos from ever being uploaded on the site. The company is still using the tool.

Responding to the judge's ruling, the company said it does not allow nudity and sexual exploitation on its network. "There's no place for this kind of content on Facebook and we remove it when it's reported to us," a spokesperson said.

Facebook did not comment on why this image -- once flagged -- wasn't caught by the PhotoDNA system.

The girl's lawyers said the photo was posted on Facebook as an act of revenge. They compared posting the photo to a method of child abuse. They also said the posts amounted to hate speech.

The girl is seeking damages for misuse of private information, negligence and breach of the Data Protection Act.

Related: Revenge porn victim: My naked photos were everywhere

Paul Tweed, a media law expert and senior partner at Johnsons Solicitors, said the case suggested a lack of consistency in how Facebook deals with nude images.

"Facebook has the tools to remove images promptly and block them, but it is not consistent...compare it with the case when Facebook took down a 1972 war photo last week and then self-policed to bring it back," he said.

Facebook ran into trouble last week for censoring the "Napalm Girl" Vietnam War photo. The image, which shows a naked girl fleeing a napalm attack, violated Facebook's ban on images of naked children, the company said.

But after fierce criticism, Facebook reversed course and allow users to post the photo.

-- Samuel Burke and Peter Taggart contributed reporting.