John Oliver, HBO, Time Warner and the writers of Last Week Tonight are being sued by Republican coal baron Robert E. Murray.

The suit, filed in Marshall County, West Virginia, alleges that the show "executed a meticulously planned attempt to assassinate the character of and reputation of Mr. Robert E. Murray and his companies" in a recent episode.

It continues: "They did this to a man who needs a lung transplant, a man who does not expect to live to see the end of this case."

The suit was entirely expected, with Oliver even predicting it during the episode in question as Murray has sued several media outlets recently including the New York Times in May. He previously sent the show its first cease-and-desist letter.

Oliver tore into Murray for not doing enough to protect miners' safety. Murray took particular issue in the suit with the comedian's discussion of the collapse of one of Murray's mines in Utah - Oliver attributed it to unauthorised mining practices, while Murray blamed an earthquake.