Renee Zellweger "tried" to meet Liza Minnelli before she started filming 'Judy'.

Renee Zellweger

Renee Zellweger

The 50-year-old actress portrays late entertainer Judy Garland in the upcoming biopic and did her best to reach out to the 'Wizard of Oz' star's family ahead of filming but had no success.

She said of Liza: "We have a really close mutual friend. One of my best friends, actually. And I had spoken with him about trying to find her. But, I guess I wasn't successful in that."

If she had been able to connect with Liza's family, the 'Jerry Maguire' actress wanted to find out what they wanted to see in the movie.

She told USA Today newspaper: "My intention was to share with (Garland's children) how I perceived the project and what I was hoping from it, and to ask what they might hope from it."

And Renee insisted she had no intention of asking personal questions about Judy - who died from an accidental overdose aged 47 - because she respects their right to privacy.

She explained: "I feel like anything that she or that they would want to share about their mom and the world, they have shared. And anything that they've chosen to keep private is treasure, and I would never in my life imagine to impose in that way."

While the Oscar-winning star regarded the movie as a "love affair" and a "research project" she was passionate about, it was perhaps no surprise Liza rejected her efforts to meet as she has previously slammed the biopic.

She wrote last year: "I have never met nor spoken to Renee Zellweger. I do not approve nor sanction the upcoming film about Judy Garland in any way."