Australia's competition regulator has begun an inquiry into whether the influence of Facebook and Google has harmed the media sector.
It will investigate whether the disruption of the news media by the US tech giants has been detrimental to consumers and publishers.
The government ordered the inquiry as part of wider media reforms.
Traditional media companies have been squeezed by online rivals and suffered a sharp drop in advertising revenues.
The Australian Competition and Consumer Commission (ACCC) inquiry, announced on Monday, will examine the effect that search engines, social media and other digital content aggregation platforms are having on media and advertising markets.
ACCC chairman Rod Sims said in a statement the inquiry "will study how digital platforms such as Facebook and Google operate to fully understand their influence in Australia".
Mr Sims said it will investigate whether digital platforms are "exercising market power in commercial dealings to the detriment of consumers, media content creators and advertisers".
The government ordered the investigation as part of wider reforms amid rising concerns about the future of the media sector following years of falling profits, newsroom job cuts and the rise of fake news.
The inquiry will have power to demand information from Google, Facebook and other firms, as well as hold hearings.
The ACCC is expected to produce a preliminary report late next year.