Update: Twitter has informed us directly that the issue has been resolved.

Update: We have heard back from Twitter and they said that they are looking into the situation.

500px is encountering issues with Twitter in which the Toronto, Canada-based photography social network’s links are being blocked. The reason, as TNW has learned, is that users are receiving automated messages on the web saying that the links are forbidden because “they contain malware or are spammy.” 500px co-founder and COO Evgeny Tchebotarev says that these messages are incorrect.

For at least the past 13 hours, users who have been sharing links to their photos on 500px to Twitter have found their links being replaced with an “unsafe site” error message. Tchebotarey says that his company has reached out to Twitter multiple times, but unfortunately hasn’t heard back yet.

Snap 2013 02 23 at 10.30.40 730x366 500px bemoans Twitter link blockade, claims auto generated citations about malware and spam are false [Update: Fixed!]

It seems that this is only limited to Twitter and that 500px users can still share photos to other social networks. If you also share using the company’s iOS app, you will run the same issue.

Tchebotarev has taken to Twitter to inform his users and it’s there where we came across a tweet from designer Calvin Tennant who pointed out that on Google’s safe browsing service, 500px has not been marked as suspicious.

Could this be another issue over 500px’s nudity issue that it faced with the Apple App store last month? Could Twitter be concerned that photos shared there may be borderline mature and its filters have labeled it suspect? According to Twitter’s media policy, this doesn’t appear to be the case as the service will display a message warning you of potential mature content before it’s displayed:

Images that have been marked as containing sensitive content will have a warning message that a viewer must click through before viewing the image. Only users who have opted in to see possibly sensitive content will see these images without the warning message.

Twitter’s policy also makes it clear that it does not mediate content shared on the site, except that which isn’t permissible by law:

We do not mediate content, whether that content is an image or text; however, some content is not permissible by law. All content should be marked appropriately as per our guidelines. You may not use our service for any unlawful purposes or in furtherance of illegal activities. International users agree to comply with all local laws regarding online conduct and acceptable content.

Who knows — it may just be a glitch in the system.

We have reached out to Twitter for comment and will update this if we hear back.

Photo credit: Tom Shaw/Getty Images