Lady Gaga’s passionate defence of fellow singer Kesha has been revealed in explosive new court documents.

The newly unsealed deposition, which took place in September 2017, also reveals a fiery exchange between Gaga and producer Dr Luke’s lawyer, according to website The Blast.

During questioning about Kesha’s claims of sexual assault against Dr Luke, Gaga castigated the producer’s lawyer: “Do you know what it’s like for survivors? Do you know what it’s like to tell people? Don’t you roll you eyes at me. You should be ashamed of yourself,” the website reported.

According to The Blast, Gaga was questioned about her initial conversation with Kesha about the alleged sexual assault.

“What I recall was her immense sadness and depression and fear. She was visibly very different than when I had seen her before, and — but I can’t say specifically what we spoke about. I just recall it was emotional and I wanted to be there for her.”

Gaga also described how she initially met Kesha at Dr Luke’s home, and that Kesha had been in a back room with only underwear on.

Things reportedly boiled over when Dr Luke’s lawyer asked Gaga whether she believed being accused of rape had damaged his reputation.

“Reputation, if you are asking about his reputation in the world, I don’t feel at liberty to speak for the entire world,” she said.

“So if you are asking what my view is of his reputation, I made my view of him and his reputation when I saw her in that back room. That was an image that — of something that happened to me, and I felt and knew in my heart that she was telling the truth, and I believe her.”

Dr Luke’s lawyer insinuated that Gaga could not have knowledge about what had happened between the pair.

“Yes, I do have knowledge,” Gaga reportedly said. “She told me he assaulted her.”

The lawyer bit back saying that “when men assault women, they don’t invite people over to watch”.

Gaga countered his attack, saying she had “factual knowledge of [Kesha’s] depression”.

“I have factual knowledge of her need for support and love. I have factual knowledge of the spiral that I watched that girl go down. I have factual knowledge of trauma. I am informed and intelligent about this issue. That girl has experienced serious trauma and she is in the middle of the right now. And you are all a party to it.”

The singer reportedly cried during her testimony, which her lawyers said was a result of PTSD reactions as a sexual assault survivor.

Kesha sued the music producer in 2014 for alleged sexual assault, gender violence, emotional abuse and violation of business practices, asking to be released from her contracts with him.

In 2016, a judge denied this request and she continued to release new music with his approval.

Last September, a US judge ruled that Luke and his lawyers would be able to present documents supporting their claim that Kesha had conspired a smear campaign against him.

Kesha is reportedly asking for an estimated $A55 million in damages from the producer.

Kesha has said her career has suffered over the incident.