The National Geographic Channel has pulled Neil deGrasse Tyson’s “Star Talk” show after sexual misconduct allegations have surfaced against the astrophysicist.

“When we learned of the allegations and the investigation began (Nov. 30) we opted to stop airing new episodes until the investigation concludes,” a Nat Geo spokesperson told AfroTech.

First reported by Variety, the cancelation happened near the beginning of the show’s fifth season.  Three episodes out of a 20 episode order aired in November and more were supposed to air through December.

Tyson is accused of sexual misconduct by Bucknell University’s Dr. Katelyn N. Allers and his former assistant Ashley Watson. Allers claims that Tyson groped her at a 2009 event and Watson says that he made inappropriate advances toward her.

Tyson has previously received claims of sexual misconduct. In the 1980s musician Tchiya Amet claimed he raped her, according to Variety.

Tyson responded to the claims in a December Facebook post.

“In any claim, evidence matters. Evidence always matters. But what happens when it’s just one person’s word against another’s, and the stories don’t agree? That’s when people tend to pass judgment on who is more credible than whom,” Tyson. “And that’s when an impartial investigation can best serve the truth – and would have my full cooperation to do so.”

Tyson has canceled future talks in Orlando, Jacksonville, and Boca Raton, FL since the allegations.

Another show featuring Tyson, “Cosmos: Possible Worlds,” is set to premiere in March and expected to air in 172 countries. The fate of that program has not been announced by Nat Geo.