"In my opinion the Washington Post is nothing more than an expensive (the paper loses a fortune) lobbyist for Amazon," Trump said via Twitter. "Is it used as protection against antitrust claims which many feel should be brought?"
Trump said in a separate tweet that the Washington Post published a lot of critics of the US president since the Supreme Court has decided that states can make online customers pay sales taxes.
READ MORE: Trump Slams Amazon for 'Putting Many Thousands of Retailers Out of Business'
Trump has frequently criticized media, including the Washington Post for bias toward him. In March, Trump said that Amazon pays little taxes to state and local governments and puts many competitors at a disadvantage. Trump also claimed the company is costing the US Postal Office a lot of money.