HBO has been slapped with a lawsuit after "Last Week Tonight" host John Oliver dedicated a large portion of his latest Sunday show to mocking a coal company that sent him a cease-and-desist letter.

"The false and defamatory statements in this broadcast severely and destructively impact Mr. Murray … as well as coal mining itself," Murray Energy Corp. said in a news release, according to a report from the Daily Beast on Wednesday. The company, which says it is the largest privately owned coal company in the U.S., has a history of issuing lawsuits against the media, including a recent one against the New York Times for defamation.

An updated version of the report said the suit was filed Wednesday in the circuit court of Marshall County, W.Va., alleging a "meticulously planned attempt to assassinate the character" of CEO Bob Murray, "a man who needs a lung transplant, a man who does not expect to live to see the end of this case," and his companies. The text of the complaint also states Murray's health degraded after Oliver's latest show aired and claimed that his website was hacked.

Oliver said on his show Sunday that they reached out for comment from the company on the segment that was being planned and received a cease-and-desist letter warning against any efforts to "defame, harass, or otherwise injure" Murray or the company.

That only emboldened Oliver, who said the segment, which was focused on the coal industry and promises made to it by President Trump, originally wasn't originally going to spend much time focusing on Murray or his company. That didn't end up being the case.

"I have to proceed with caution," Oliver quipped. "I'm not going to say, for instance, that Bob Murray looks like a geriatric Dr. Evil, even though he clearly does."

Oliver later invited a person dressed up as a squirrel onstage to address a potential lawsuit (the bit was a play on an alleged conversation Murray had with a squirrel, which the company denies.)

"Hey, Bob. Just wanted to say, if you plan on suing, I do not have a billion dollars. But I do have a check for three acorns and 18 cents ... it's made out to ‘Eat Shit, Bob,'" said the squirrel, named "Mr. Nutterbutter."

HBO stood by Oliver in a statement reported by the Daily Beast.

"While we have not seen the complaint, we have confidence in the staff of Last Week Tonight and do not believe anything in the show this week violated Mr. Murray's or Murray Energy's rights," HBO said.