A source on American Idol has described Lea Michele as a "nightmare" to work with when she made a guest appearance on the show last year.

The former Glee actress has been the subject of a string of allegations of poor behind-the-scenes behaviour in recent weeks, with a number of former co-stars and colleagues accusing her of disrespectful behaviour on set.

Michele appeared on Idol in April 2019 to promote her Little Mermaid concert with a performance of 'Part of Your World'.

"She was a nightmare on Idol," a show source recalled to The Sun. "One contestant asked for a picture and she didn't even say no. She just walked away.

"She was yelling at the audio team saying they didn't understand her and that she can't go on like this. She was just a diva.

"The contestants were so excited about her appearance and then she was a nightmare to everyone. She is truly just awful."

The 33-year-old issued an apology for how her past actions had been "perceived" after the first allegation came out but has maintained a social media silence since.