Officials from the Justice Department are conducting an investigation to see if cable companies are acting improperly to quell competition from online video, according to the Wall Street Journal.

Justice Department officials have questioned Comcast Corp., Warner Cable Inc. and other cable companies about companies limiting the amount of data subscribers can download each month, people familiar with the matter told the Wall Street Journal. Cable companies provide high-speed Internet access in addition to television channels.

Many Americans forego getting cable television and use the broadband Internet to view individual shows and movies online through services such as Netflix, Hulu and Amazon, according to the article.

In its TV investigation, Justice Department officials are looking closely at the data limits providers such as Comcast and AT&T Inc. have used to combat online video traffic, according to the article. The companies say the data caps are needed in order to stop heavy users from overwhelming their networks.