Renee Zellweger was left horrified when her prosthetic nose broke off as she kissed co-star Finn Wittrock in the upcoming Judy Garland biopic.

The 50-year-old actress relied on prosthetics to make her look as much like the late singer/actress as possible for the film, simply titled Judy. But using such special effects had its downside - as Renee found out while shooting a passionate scene alongside Finn, who plays Judy's fifth husband Mickey Deans.

"I had no idea!" she told Entertainment Tonight, adding that some part of the fake nose's material or adhesive oozed a milk-like substance when the pair pushed their faces together for the kiss. "I did not know until this kissing scene and I look at him with horror and I realise, 'Am I more upset that I got that on his face - and we haven't cut so I can't be touching his face in a way to try and get it of - or that it's attached to my head and there's so much more where that came from?'

"The glue and the thing and the chemicals or something, I don't know, and some of it would just sneak out the crevice (on the side)," Renee laughed, adding sarcastically: "(Very) glamorous."

The Oscar-winning actress received a standing ovation from the audience after the film screened at the Toronto International Film Festival on Tuesday night. The Chicago star eventually told the crowd to finish their applause, saying, "OK quit it - you're messing up my make-up!"

The actress is being tipped for an Oscar nomination for her performance in Judy, which hits cinemas later this month.