The woman, who does not use her name in the lawsuit and goes by Jane Roe, claims the assault occurred when she travelled from Nashville to Los Angeles with the singer, who was performing at the 2019 Grammy Awards.

The lawsuit - filed on Thursday in the Los Angeles Superior Court - alleges that despite Brooks normally travelling with an entourage, she and Brooks flew alone to the event on his private jet, and that he had booked just one hotel suite for both of them.

The woman claims that in the suite, he appeared naked in the doorway to the bedroom and raped her.

Brooks said the lawsuit is an attempt at extortion for "millions of dollars".

In a statement to the PA news agency, he said: "For the last two months, I have been hassled to no end with threats, lies, and tragic tales of what my future would be if I did not write a check for many millions of dollars.

"It has been like having a loaded gun waved in my face.

"Hush money, no matter how much or how little, is still hush money. In my mind, that means I am admitting to behaviour I am incapable of - ugly acts no human should ever do to another."

The suit goes on to say Books proceeded as though nothing had happened and expected her to do his hair and make-up immediately after.

The woman further alleges that earlier in that same year, when she was at Brooks' home, he had appeared naked in front of her, grabbed her hands, and put them on his genitals.

Pre-empting the allegations, Brooks filed a separate lawsuit in federal court in Mississippi last month in which both him and the woman were anonymous, Thursday's lawsuit claims.

In court filings in that case, the plaintiff, named as John Doe, said the allegations were "wholly untrue", and he first learned of them in July when she threatened to publicly sue him unless he gave her millions of dollars.

He asked a judge to stop the woman from "intentional infliction of emotional distress, defamation and false light invasion of privacy".

Brooks added in a statement PA: "I want to play music tonight. I want to continue our good deeds going forward. It breaks my heart these wonderful things are in question now.

"I trust the system, I do not fear the truth, and I am not the man they have painted me to be."

The lawsuit by Jane Roe claims that on top of the two described incidents, Brooks exposed himself to her on many other occasions, talked about sexual fantasies with her and sent her explicit text messages.

She says she was forced to keep working for him because of financial hardship, which he knew about and took advantage of.

The unnamed claimant is believed to have also worked for Brooks' wife, fellow country singer Trisha Yearwood, since 1999.

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Oklahoma-born Brooks, 62, was the biggest star in country music of the 1990s, with hits including Friends In Low Places and The Thunder Rolls.

He remains the number one-selling individual artist in US history with 20 Billboard no 1 singles and 157 million record sales, according to his official website.

In March this year, he finished a residency at the Colosseum at Caesars Palace, Las Vegas.

He married fellow country star Yearwood in 2005.