Gwyneth Paltrow was left mortified during an appearance at the Oscars when her breasts began leaking milk all over her dress.

The Iron Man actress was asked to reveal her most embarrassing wardrobe malfunction to date during an appearance on U.S. Tv show Watch What Happens Live, and the Iron Man star revealed attending the Academy Awards ceremony as a new mother ended in a major mishap.

She tells host Andy Cohen, "My breast milk kind of decided it was time to come, you know... And I was at the Oscars, and so I hadn't pumped breast milk in a long time. Luckily, the show was over and I had already presented, but...yeah, it wasn't good. It's not a good look at all."

Paltrow is a mother to two children, daughter Apple and son Moses, with her estranged husband Chris Martin.

The revelation comes just days after fellow Hollywood actress Meryl Streep opened up about her own breast milk disaster which ruined her dress at the Golden Globe awards in 1979.