Shannen Doherty leaving ABC Studios after appearing on 'Live with Regis and Kelly', New York City, USA - 05.09.08

The actress was dubbed a wildchild on hit 1990s TV show Beverly Hills, 90210 for showing up to work tired and moody - but now she insists it was because she'd spent the night in hospital at her sick father's bedside.

Doherty's dad suffered a series of health setbacks during his daughter's tenure on the show - but she chose to deal with them privately, rather than approaching co-stars or producers for help.

She tells Radar magazine, "I'm very private about certain things, and my own cast mates never knew about my dad and his medical problems.

"Nobody knew I was in the hospital 'til five in the morning and came straight to the set. People just thought, 'She's unprofessional.'"

"Back then, you know, if I seemed moody, you try having a father be that sick and calling and saying, I don't think I can work today,' and being told, 'No, no, no. You're working or we're suing you.' It's brutal."

Source: WENN