Parents around the country are in outrage over moldy sippy cups from a popular brand.

FOX's Alex Hein has more:

This is Housecall for Health.

Outraged parents are taking to social media to share photos of moldy Tommee Tippee sippy cups and it calls for the manufacture to investigate the potential health harm.

Parents are claiming the mold on the popular cups can only be seen when opening their anti-leak spout. One parent said that his son's sickness persisted and he couldn't figure out why until he opened the spout of his sippy cup and discovered mold.

Photos of the cups have been shared more than 45,000 times with warnings about mildew.

The company issued a statement saying the mold issue is likely being caused by the use of non-recommended liquid, which includes thick formula milk, pulpy juice, and warm liquids.

The company further said they contacted a concerned parent and are talking to him about his use of the cup. They apologized and are following up on any concerns. The statement also advised parents to clean the cups regularly and said to avoid any potential harm, they would be making a transparent valve available in the future.

For more on this story check foxnewshealth.com.

Housecall for Health, I'm Alex Hein, FOX News.