The current season of a National Geographic Channel series has been put on hold, with the cable channel saying today that new episodes of the show, “Star Talk,” will not air until an investigation is completed into allegations against the show’s host, Neil deGrasse Tyson.

The AP reports that the prominent astrophysicist and popular television personality is accused of sexual misconduct.

“Last December, National Geographic Networks and Fox said they would examine claims that Tyson behaved in a sexually inappropriate manner toward two women,” the story reports. “Tyson was host of ‘Cosmos: Possible Worlds’ on Fox in 2014, and a new edition of the series was set to air this year on National Geographic.”

“Tyson has denied an accusation that he groped a woman and denied making sexual advances toward a production assistant at his home,” the report adds. “He has said he will cooperate fully with what he called an impartial investigation.”