Michelle Williams and Spike Jonze split

Michelle Williams has ended her romance with director Spike Jonze, blaming their break-up on "impossible timing".

The Brokeback Mountain actress originally began dating the filmmaker in July last year, only months after Williams's ex-fiancé Heath Ledger died from an accidental drug overdose.

However, Williams revealed that she is no longer in a relationship with Jonze during a new interview with Vogue - admitting that she is still grieving the loss of Ledger.

She said: "The timing was impossible. I thought falling in love again was the only thing that was going to save me from the pain. This erroneous idea: it just makes things more complicated."

The star also revealed that she came close to breaking down at the end of 2008 because the pain was too much.

She added: "I was holding it together by a string and a paperclip in the fall and winter. I didn't know if I could keep it all together... You console yourself by saying it's all a deepening process. But it's weird. After the first year, the pain is less intense - it's less immediate."

> Williams opens up about Ledger daughter