Actress Naya Rivera has come clean about her rumoured feud with Glee co-star Lea Michele, revealing they did not speak to each other while filming the show's final season.

Reports of an on-set rivalry were first sparked in 2014, when the two allegedly became embroiled in a heated fight, prompting series creator Ryan Murphy to allegedly fire Naya and leave her character, Santana Lopez, out of the sixth and final season.

Naya's publicist and Murphy both dismissed the reports, while Lea, who played Rachel Berry, also noted she was shocked about "the amount of things that can just be completely made up".

But now Naya has opened up about their tense relationship in her new autobiography, Sorry, Not Sorry: Dreams, Mistakes & Growing Up, revealing they used to be friends.

"One of the Glee writers once said that Lea and I were like two sides of the same battery and that about sums us up," Naya wrote. "We are both strong willed and competitive - not just with each other but with everyone - and that’s not a good mixture.

"As the show progressed, though, that friendship started to break down, especially as Santana moved from a background character to one with bigger plot lines and more screen time. I think Rachel - erm, I mean Lea - didn’t like sharing the spotlight. On top of that, she had a hard time separating work from our outside friendship, whereas it was a lot easier for me."

"I’m not offended when people offer feedback or criticism, and if things get heated on set, I try to keep perspective," she continued. "We’re all stressed, yes, but we’re all working toward the same goal, so laugh it off and keep it movin’. Lea was a lot more sensitive, though, and it seemed like she blamed me for anything and everything that went wrong."

Naya added that by the final season of Glee, it was a complete cold war, and she doubts they'll be friends in the future, revealing, "If I'd complained about anyone or anything, she'd assumed I was b**ching about her. Soon, she started to ignore me, and eventually it got to the point where she didn’t say a word to me for all of season six. Lea and I definitely weren’t the best of friends, and I doubt we’ll ever sit on her couch and eat kale together again, but the rumors of our ‘feud’ were blown out of proportion."

Naya also divulged her thoughts on Lea's unlikely romance with their co-star Cory Monteith, whom Lea dated from 2011 up until his death in 2013.

"When Cory and Lea started dating, it was a total surprise," Naya wrote. "The more serious they got, the less Cory hung out with us and the more he seemed like a different person. One year he came back from the break between seasons super skinny. He said he’d been spending a lot of time at the gym and was trying to be responsible...

"My personal feelings for Lea aside, I knew that she wasn’t a partier, so I felt like maybe their relationship could actually be good for him. I was happy for Cory to have a stable influence in his life, wherever it was he found it.”

Monteith died of a drug and alcohol overdose in July, 2013, just weeks before he was scheduled to begin filming on Glee's fifth season.