Renowned astrophysicist Neil deGrasse Tyson will be investigated by Fox and National Geographic Networks after allegations of sexual misconduct were levelled against him.

Patheos.com, which describes itself as a website for "global dialogue about religion and spirituality," published accounts Thursday from two women who say that Tyson behaved in a sexually inappropriate manner with them. Tyson was host of Cosmos on Fox in 2014 and a new edition of the series was to air on National Geographic next year.

In a lengthy Facebook post published Saturday, deGrasse Tyson addressed each of the allegations in detail, providing his own version of events and vehemently denying any wrongdoing.

"I'm the accused, so why believe anything I say? Why believe me at all?" he wrote.

He also said he welcomes the independent investigation.

"Accusations can damage a reputation and a marriage. Sometimes irreversibly. I see myself as [a] loving husband and as a public servant — a scientist and educator who serves at the will of the public."

In a statement, the producers of Cosmos said: "The credo at the heart of Cosmos is to follow the evidence wherever it leads. The producers of Cosmos can do no less in this situation."

They said they will conduct a thorough investigation. Meanwhile Fox and National Geographic said Friday evening that they only recently learned of the allegations and were reviewing them.

Besides numerous TV appearances, Tyson is also the director of the Hayden Planetarium at the American Museum of Natural History in New York City.