The Justice Department has warned the Academy Awards that banning Netflix from the Oscars could draw an antitrust investigation.

Antitrust chief Makan Delrahim sent a letter to the academy warning that any changes that limited eligibility for the industry's highest honors 'may raise antitrust concerns,' Variety reported on Tuesday. Antitrust laws are used to break up monopolies and outlaw anti-competitive behavior.

The Academy of Motion Picture Arts & Sciences has been considering changing eligibility rules to require a broader theatrical release to qualify for the Oscars in a move widely seen as a dig at big streamers such as Netflix.

In the past, Netflix has achieved eligibility for the Oscars using a practice called 'four-walling', or renting a handful of theaters in order to screen its streaming movies.

Roma director Alfonso Cuaron shows off his Oscars for director, cinematography, and foreign language film last month. Netflix achieved eligibility for the film by 'four-walling' theaters

Currently, feature films must screen for paid admission at least three times daily on seven consecutive days in a Los Angeles County commercial theater in order to qualify for the Oscars.

An academy spokesperson confirmed it had received the letter and said any rule changes would be considered at an April 23 meeting.

A source close to Netflix said the company was not involved with or aware of the Justice Department's letter.

One member of the Academy's board of governors expressed surprise to the Wall Street Journal that the Justice Department was wading into the adjudication of a Hollywood awards show.

'Can't a contest set their own rules?' said the person, who asked not to be named.

The issue of how Netflix fits into, or threatens, the theater business also dominated a press conference on Tuesday at CinemaCon, the theater industry trade show in Las Vegas.

'All of your questions from the first 17 minutes or whatever are about Netflix,' grumbled John Fithian, president and chief executive of the National Association of Theatre Owners.

John Fithian, left, president and CEO of the National Association of Theatre Owners (NATO), and Charles Rivkin, chairman and CEO of the Motion Picture Association of America (MPAA), address the audience during CinemaCon 2019 at Caesars Palace on Tuesday

He insisted that Netflix and theaters can happily co-exist, citing data that showed the biggest consumers of streaming video visit theaters more often. He also said Netflix had helped revive interest in documentaries, which had helped draw people to theaters to see them.

Earlier, Fithian told a crowd in a Caesars Palace theater that films reached their full potential only with a 'robust theatrical release.'

He spoke just after 'Crazy Rich Asians' director Jon M. Chu said his film would not have had as big an impact if it had debuted on a streaming service.

Netflix is a member of the Motion Picture Association of America, the trade association for Walt Disney Co, Warner Bros. and other movie studios.

'We are all stronger advocates for creativity and the entertainment business when we are working together ... all of us,' MPAA CEO Charles Rivkin said on the CinemaCon stage.

John Fithian, president and CEO of the National Association of Theatre Owners (NATO), discusses some of the top-grossing films of 2018 during CinemaCon 2019 on Tuesday

Both Rivkin and Fithian noted that box office receipts hit a record $11.9 billion in the United States and Canada in 2018 even as Netflix released dozens of original movies.

Mitch Neuhauser, managing director of CinemaCon, also was asked to address the issue when he wandered into a work room for reporters.

'Streaming is not a problem!' he exclaimed, noting that there are limits to how much people can stand to stay at home with all of the modern conveniences including grocery delivery.

'We've got to get out of the house. We are talking about becoming a society of hermits!'