Best-selling English writer Neil Gaiman has denied accusations of rape and sexual assault, insisting he had never had non-consensual sex with anyone.

The science fantasy author of popular works such as American Gods and Good Omens hit back after the New York Magazine on Monday published an in-depth investigation into the allegations which first emerged six months ago.

The magazine cited testimonies from eight women, including four who had not previously spoken out, about rough and degrading assaults which they claimed took place when they were in their 20s.

One of the women, Scarlett Pavlovich, recounted how she was assaulted by the writer when she was 22, and working as a baby-sitter for Gaiman in New Zealand in early 2022.

She said he had invited her to take a bath in a tub which was installed outside in the garden, before slipping in naked to join her.

She described in graphic detail how he brushed aside her protests of "No, no" and sexually assaulted her.

Pavlovich however remained in contact with the author and signed a confidentiality agreement in exchange for some 9,000 euros ($9,200).

Other women had similar stories, with some saying they had received money to pay for counselling sessions.

"I'm far from a perfect person, but I have never engaged in non-consensual sexual activity with anyone. Ever," Gaiman wrote Tuesday on his website.

"As I read through this latest collection of accounts, there are moments I half-recognise and moments I don't, descriptions of things that happened sitting beside things that emphatically did not happen," he added.

And he maintained that reading back over messages he had exchanged with the women involved, he believed they reflected "two people enjoying entirely consensual sexual relationships and wanting to see one another again."

"I was obviously careless with people's hearts and feelings, and that's something that I really, deeply regret. It was selfish of me."

London-based Tortoise media was the first outlet to reveal the accusations spanning two decades against Gaiman in a series of podcasts released in July.

One woman, identified only as K, said she was a huge fan of Gaiman's work and had begun a relationship with him when she was 20 in the early 2000s, alleging she submitted to rough and painful sex that "she neither wanted nor enjoyed."

The award-winning author is also known for his comics and graphic novels which have attracted a younger generation to his writings.

Some of his books, including The Sandman, have been turned into TV adaptations.

But as the allegations emerged, Disney announced in September it had halted production on its movie based on Gaiman's young adult novel The Graveyard Book about a young boy raised by ghosts.

And Amazon's Prime Video revealed in late October that its popular series of Good Omens, starring Scottish actor David Tennant as a demon and Michael Sheen as an angel, would finish its run with a third season reduced to just one 90-minute program.