YouTube has been reportedly slapped with a fine by the Federal Trade Commission (FTC) over violating federal data privacy laws for children.

The agency has finalised a settlement which found that Google, YouTube's parent company, did not do enough to protect the privacy of children who use its video-streaming service, people familiar with the matter told The Washington Post.

The settlement also claims that YouTube improperly collected children's data, breaching the Children's Online Privacy Protection Act (COPPA), which prohibits the tracking and targeting of users younger than 13.

While the exact amount of the fine is unclear, YouTube is expected to pay multimillion-dollars in damages.