Renowned astrophysicist Neil deGrasse Tyson says he will cooperate fully with an "impartial investigation" into allegations of sexual misconduct that have been levelled against him.

Key points: One woman said she was "felt up" by Tyson while he was looking at her tattoo of the solar system

One woman said she was "felt up" by Tyson while he was looking at her tattoo of the solar system Another said he made inappropriate advances during a wine and cheese event at his house

Another said he made inappropriate advances during a wine and cheese event at his house Tyson denied both accusations, and said he welcomed the investigation

Patheos.com recently published accounts from two women saying Tyson behaved in a sexually inappropriate manner towards them.

In the report, astronomer Katelyn Allers said she was "felt up" by Tyson when he reached into her dress while looking at her tattoo of the solar system that stretched from her arm to her back and collar bone area.

Ashley Watson, a former assistant to Tyson, was also quoted as saying she quit her job after he made inappropriate sexual advances when he invited her to share wine and cheese at his home.

Patheos previously reported allegations by musician Tchiya Amet claiming Tyson drugged and raped her when they were graduate students at the University of Texas.

In a Facebook post on Saturday, Tyson denied the accusation he groped Dr Allers, saying he was only searching for Pluto in her tattoo and never meant to make her uncomfortable.

"A colleague … came up to me to ask for a photograph. She was wearing a sleeveless dress with a tattooed solar system extending up her arm," he said in the post.

"And while I don't explicitly remember searching for Pluto at the top of her shoulder, it is surely something I would have done in that situation. As we all know, I have professional history with the demotion of Pluto … so whether people include it or not in their tattoos is of great interest to me.

"I was reported to have 'groped' her by searching 'up her dress', when this was simply a search under the covered part of her shoulder of the sleeveless dress.

"I only just learned [nine years after] that she thought this behaviour creepy. That was never my intent and I'm deeply sorry to have made her feel that way."

He also denied he made advances towards his former assistant, saying they simply had a "fun, talkative relationship".

Ms Watson told The Washington Post Tyson took off his shirt so he was only wearing an undershirt, and spoke about how people needed "release" and asked what hers was.

Tyson said she freely chose to come to his home, and later told him she was "creeped out" by the wine and cheese evening.

"She viewed the invite as an attempt to seduce her … at that last meeting in my office, I apologised profusely. She accepted the apology," he said.

Fox and National Geographic Networks have said they will conduct a thorough investigation.

Tyson was host of Cosmos: Possible Worlds on Fox in 2014 and a new edition of the series was to air on National Geographic next year.

ABC/AP