The 'Fashion Police' hosts have mocked Elsa Pataky's Oscars dress.

The outspoken stars of the E! show were less than impressed with the turquoise gown with a drop waist Chris Hemsworth's heavily pregnant wife donned for the Academy Awards on Sunday (02.03.14), calling her beaded floor-length red carpet look unflattering and likening her baby bump to a ''beer belly''.

George Kotsiopoulos said: ''The last thing I wanna do is rip on a pregnant woman. But it's a horrible dress on her. It doesn't look like a baby bump, it looks like a beer belly.''

Kelly Osbourne added: ''It's just not the appropriate dress to wear if you are pregnant, you have to go with an empire style, or just dress like Olivia Wilde.''

Giuliana Rancic also chimed in: ''I have to say pregnant or not, I just don't like this dress.''

However, Joan Rivers' remark about Elsa - who is expecting twins - appears to have caused the most outrage on social media as she was poking fun of her size.

Joan deadpanned, ''I know why she's huge. I saw her sonogram'', as a picture of Ellen DeGeneres' now infamous selfie with 10 of Hollywood's biggest actors appeared on screen.

The catty comments didn't go down well with fans, who were quick to bite back when the clip appeared on YouTube.

One wrote, ''Fashion Police, you're just so rude - she's very pregnant and beautiful in this dress'', while another defended the Spanish-born actress, saying, ''She's pregnant, she can wear whatever she wants, she's gorgeous.''